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The aim of this study was to investigate the inhibitory effect and the underlying mechanism of ethacrynic acid (EA) on the contraction in mice. BL-420S force measuring system was used to measure the tension of mouse tracheal rings. The whole cell patch clamp technique was utilized to record the channel currents of airway smooth muscle (ASM) cells. The calcium imaging system was used to determine the intracellular Ca 2+ concentration ([Ca 2+ ] i ) in ASM cells. The results showed that EA significantly inhibited the high K + (80 mmol/L) and acetylcholine (ACh, 100 µmol/L)-induced contraction of mouse tracheal rings in a dose-dependent manner. The maximal relaxation percentages were (97.02 ± 1.56)% and (85.21 ± 0.03)%, and the median effective concentrations were (40.28 ± 2.20) μmol/L and (56.22 ± 7.62) μmol/L, respectively. EA decreased the K + and ACh-induced elevation of [Ca 2+ ] i from 0.40 ± 0.04 to 0.16 ± 0.01 and from 0.50 ± 0.01 to 0.39 ± 0.01, respectively. In addition, EA inhibited L-type voltage-dependent calcium channel (LVDCC) and store-operated calcium channel (SOCC) currents in ASM cells, and Ca 2+ influx. Moreover, EA decreased the resistance of the respiratory system (Rrs) in vivo in mice. These results indicated that EA inhibits LVDCC and SOCC, which results in termination of Ca 2+ influx and decreases of [Ca 2+ ] i , leading to relaxation of ASM. Taken together, EA might be a potential bronchodilator.

Objectives: To identify the site that emulsified sevoflurane influences in the nerve system., Methods: Thirty-six healthy New Zealand rabbits were randomly and equally divided into low concentration emulsified sevoflurane group [4 mL/(kg·h)], medium concentration [6 mL/(kg·h)]group, high concentration group[10 mL/(kg·h)]and intralipid control group. Emulsified sevoflurane was infused through arterial to selectively block peripheral nerves, neuro-muscular junctions and muscle fibers. The anterior tibial muscle resting tensions and muscle contraction forces were compared before and after the infusions., Results: Significant differences of blood sevoflurane pressure between femoral veins and internal jugular veins appeared in rabbits in all the groups ( P <0.05). No significant changes in the resting tension of anterior tibia muscles were found in terms of single contractions and tetanic forces with the low and medium levels of infusion of sevoflurane compared to the base values. High level of infusion of sevoflurane resulted in decreased single contraction forces and tetanic forces of anterior tibia muscles ( P <0.05)., Conclusions: A rabbit model with selective blockage of peripheral nerves was established. Peripheral nerves are not the primary site which low and medium levels of emulsified sevoflurane influence skeletal muscle relaxations.

Objective: To investigate the effects of hydrogen sulfide (H2S) on contraction capacity of diaphragm in type 1 diabetic rats.
, Methods: Thirty-two male SD rats were randomly divided into a normal group (NC), a diabetic group (DM), a NaHS treatment group (DM+NaHS) and a NaHS group (NaHS) (n=8). Intraperitoneal injection of streptozotocin was utilized to establish diabetic rat model. After the modeling, the rats in the DM+NaHS and the NaHS groups were intraperitoneally injected with 28 μmol/kg NaHS solution. 8 weeks later, the diaphragm contractility was assessed by isolated draphragm strips perfusion. The peak twitch tension (Pt), maximum tetanic tension (Po) and maximal rates of contraction/relaxation (±dT/dtmax) were determined. The alterations in diaphragm ultrastructure were observed under electron microscopy. The diaphragm weight/body weight (DW/BW) was measured. The activities of succinic dehydrogenase (SDH), lactate dehydrogenase (LDH) and sarcoplasmic reticulum Ca2+ ATPase (SERCA) were analyzed by spectrophotometric method. The mRNA levels of SERCA and prospholamban (PLB) in diaphragm were detected by RT-PCR.
, Results: Compared with the NC group, there was no significant change in all measured index in the NaHS group (P>0.05), while Pt, Po and ±dT/dtmax were significantly decreased in the DM group (P<0.05). Transmission electron microscopy revealed obvious ultrastructural changes in the diaphragm. The DW/BW ratio and the activities of SDH, LDH and SERCA were decreased. The SERCA mRNA was decreased, while PLB mRNA was increased. Compared with the DM group, the diaphragm contractility and ultrastructure damage were improved in the DM+NaHS group. The DW/BW ratio and the activities of SDH, LDH and SERCA were increased. The SERCA mRNA was increased, while PLB mRNA was decreased (all P<0.05).
, Conclusion: H(2)S can enhance the contraction capacity of diaphragm in type 1 diabetic rats, which is involved in regulating the activities of biological enzymes and the gene expressions of calcium regulatory proteins.

Objective: The explore the mechanism responsible for diaphragmatic contractile and relaxation dysfunction in a rat model of sepsis., Methods: Thirty-six adult male Sprague-Dawley rats were randomized equally into a sham-operated group and two model groups of sepsis induced by cecal ligation and puncture (CLP) for examination at 6 and 12 h following CLP (CLP-6 h and CLP-12 h groups). The parameters of diaphragm contractile and relaxation were measured, and the calcium uptake and release rates of the diaphragmatic sarcoendoplasmic reticulum (SR) and the protein expressions of SERCA1, SERCA2 and RyR in the diaphragmatic muscles were determined., Results: The half-relaxation time of the diaphragm was extended in both the CLP-6 h and CLP-12 h groups with significantly reduced maximum tension declinerate and the peek uptake rate of SERCA (P<0.01). Diaphragmatic maximum twitch force development rate, the maximal twitch, tetanus tensions and the peek release rate of SR decreased only at 12h after CLP (P<0.01). The expression levels of SERCA1 protein decreased significantly in the diaphragmatic muscles at 12h following CLP (P<0.01) while SERCA2 expression level and SERCA activity showed no significant changes., Conclusion: In the acute stage of sepsis, both the contractile and relaxation functions of the diaphragm are impaired. Diaphragmatic relaxation dysfunction may result from reduced calcium uptake in the SR and a decreased level of SERCA1 in the diaphragmatic muscles.

Objective: To study the therapeutic mechanism of Zhizhu Pill (ZP) for treating functional dyspepsia (FD) rats., Methods: Totally 30 ten-day-old male rats were randomly divided into the normal control group (n =10) and the model group (n = 20). The FD rat model was induced using gastric administration of 0.1% iodoacetamide (IA) combined tail clamping. The model was evaluated when rats were 8-week old. Successfully modeled rats were randomly divided into the model group (n = 10) and the ZP group (n = 10). Rats in the normal group and the model group were administered with normal saline by gastrogavage, while those in the ZP group were administered with ZP Decoction (2 mL/100 g) by gastrogavage. All medication lasted for 7 successive days. The contractile activity in in vitro longitudinal gastric muscle was recorded using Power Lab biological signal collecting system. The expression of growth hormone secretagogue receptor (GHSR) in stomach of FD rats was detected using Western blot and immunohistochemistry (IHC)., Results: Compared with the normal group, average frequencies of gastric contraction and changing rates of amplitude obviously decreased in the model group (P < 0.05). Results of Western blot and IHC showed that the expression of GHSR decreased in the model group (P < 0.01). Compared with the model group, average frequencies of gastric contraction and changing rates of amplitude obviously increased in the ZP group (P < 0.05). Results of Western blot and IHC showed that the expression of GHSR increased in the ZP group (P < 0.01)., Conclusion: ZP could promote the gastric motility in FD rats induced by gastric administration of IA combined tail clamping, and its mechanism might be related to up-regulating GHSR protein level.

Objective: To explore the protective effects of hydrogen sulfide (H2S) on diaphragmatic muscle of Type 1 diabetic rats and its anti-apoptotic mechanism.
, Methods: Thirty male Sprague Dawley rats were randomly divided into a control group, a diabetes group and a treatment group (n=10 per group). Streptozotocin (i.p.) was utilized to establish a rat model of Type 1 diabetes mellitus (DM). The DM rats were treated with NaHS solution (i.p.). After 8 weeks, the diaphragmatic muscle contractility was assessed by isolated diaphragmatic strips experiments. The peak twitch tension (Pt), maximum tetanic tension (Po), time to peak contraction (CT), half relaxation time (1/2RT) and maximal rates of contraction/relaxation (±dT/dtmax) were measured. The alterations of diaphragmtic ultrastructure were observed by electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and caspase-3 were analyzed by spectrophotometric method. The expressions levels of Bcl-2 and Bax mRNA in diaphragmatic muscle were detected by RT-PCR.
, Results: Compared with the control group, in the diabetic group, the Pt, Po and ±dT/dtmax were significantly reduced (all P<0.01), while CT and 1/2RT were significantly increased (both P<0.01); ultrastructure in the diaphragmatic muscle were obviously changed; the content of MDA and the activity of caspase-3 were increased (both P<0.01), while the activity of SOD was decreased (P<0.01); the ratio of Bcl-2/Bax at mRNA level was decreased (P<0.01). Compared with the diabetes group, in the treatment group, the diaphragm contractility and ultrastructural damage were improved; the content of MDA and the activity of caspase-3 were decreased (P<0.05, P<0.01 respectively), while the activity of SOD was increased (P<0.01), the ratio of Bcl-2/Bax at mRNA level was also increased (P<0.01). 
, Conclusion: The exogenous H2S can protect diaphragmatic muscle of Type 1 diabetic rats, which is related to reducing oxidative damage and suppressing cell apoptosis.

To discuss the protective effect of aralosides (AS) on I/R-induced rat myocardial injury. The adult rat ventricular myocyte ischemia model was established through perfusion with sodium lactate perfusate and reperfusion with Ca(2+) -containing Tyrode's solution simulation. The cell contraction and ion concentration synchronization determination system was applied to detect the effect of AS on single I/R cell contraction and Ca2+ transients. According to the findings, AS could increase resting sarcomere length, contraction amplitude, ± dL/dt(max), calcium transient amplitude and speed of post-reperfusion myocardial cells (P < 0.05, P < 0.01), and decrease in time for achieving 90.0% of maximum relaxation, time for achieving peak value, resting calcium ratio, contraction period [Ca2+] i, time for achieving 50.0% of maximum relaxation and attenuation rate of intracellular calcium transient (P < 0.05, P < 0.01). Therefore, it is suggested that AS improved the post-reperfusion cell contraction and injury of calcium homeostasis.

Objective: To investigate the effect of emodin on the contraction of jejunum smooth muscle and its underlying mechanisms., Methods: Rats were randomly divided into 7 groups (n = 6): control group, emodin group (1, 5, 10, 20 micromol/L), propranolol (PRO) plus emodin group, glibenclamide (GLI) plus emodin group, NG-Nitro-L-arginine Methyl Ester (L-NAME) plus emodin group, calcium free control group and calcium free emodin group. The rats were sacrificed by cervical dislocation and the small intestine was isolated. The jejunum segment specimens were mounted on an Organ Bath System with a tension transducer. The effect of emodin on contraction of jejunum smooth muscle was measured by BL-420E+ biological signal processing system and the amplitude (AM), tension (TE) and frequency (FR) of contraction were determined., Results: (1) Emodin inhibited the tension and amplitude of jejunum smooth muscle contraction in a dose-dependent manner (P < 0.05, P < 0.01) while the frequency was not obviously influenced. (2) PRO (P < 0.05) or GLI (P < 0.01) partly abolished the inhibitory effect of emodin on jejunum smooth muscle. (3) L-NAME had no obvious effect on the inhibitory effect of emodin. (4) Emodin attenuated the contraction of jejunum smooth muscle induced by calcium chloride application into calcium free K-H solution (P < 0.01)., Conclusion: Emodin obviously inhibits the amplitude and tension, while has no influence on the frequency of jejunum smooth muscle contraction in rats. Activation of beta adrenergic receptor, open of ATP sensitive potassium channels, and inhibition of the extracellular calcium influx through calcium channels of smooth muscle cell membrane might be involved in the process.

Objective: To observe the effects of Heishunpian total alkaloids on Cassia acutifolia induced mice diarrhea and contraction of isolated intestinal smooth muscle in rats., Methods: The experiment was carried out with Cassia acutifolia induced mice diarrhea model, small intestinal propulsive rate in mice was used to valuate the effect of Heishunpian total alkaloids on diarrhea mice; The effects of Heishunpian total alkaloids on contraction of isolated intestinal smooth muscle in rats and its mechanism were investigated by monitoring amplitude and tension of isolated intestinal smooth muscle in rats; The chemical constituents of Heishunpian total alkaloids were analyzed by HPLC., Results: Heishunpian total alkaloids could significantly slow down intestine propulsive motility in diarrhea mice (P < 0. 05), and reduce amplitude and tension of isolated small intestinal smooth muscle contraction in normal rats in dose-dependent manner. Heishunpian total alkaloids had a certain inhibitory effect on acetylcholine chloride and neostigmine methylsulfate strengthening small intestine smooth muscle movement, however, had no significantly effect on Atropine sulfate inhibiting small intestine smooth muscle movement. By HPLC analysis, benzoylaconitine, benzoylmesaconitine, benzoylhypaconitine were the main chemical constituents of Heishunpian total alkaloids., Conclusion: Heishunpian total alkaloids have a certain role of antidiarrheal and its mechanism may be related to antagonizing muscarinic receptors.

Objective: To determine the role of nitric oxide (NO) in intestinal motility dysfunction in rats subjected to hemorrhagic shock (HS)., Methods: Sixteen male Wistar rats were randomly and equally divided into two groups. The HS model of rat was induced by bleeding from femoral artery. After animal models were made, different inducers were added, and duodenum samples were harvested for the determination of contractile response to acetylcholine (ACh) in vitro, activities of inducible nitric oxide synthase (iNOS), contents of NO in tissue, and morphological changes., Results: The spontaneous contraction of intestinal smooth muscle and contractile response induced by ACh were significantly decreased at 180 minutes in HS group, compared with control group, the contractile response induced by ACh of intestinal smooth muscle was decreased by almost 60% (0.40±0.11 g×mm(-2)×s(-1) vs. 1.00±0.20 g×mm(-2)×s(-1), P<0.01). The inhibitor of iNOS N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) could significantly restore the suppressed contractile response of smooth muscle strips obtained from HS rats (0.97±0.25 vs. 0.40±0.11, P<0.01). Moreover, the inhibitor of soluble guanylyl cyclase 1H-[1,2,4] Oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) also improved the contractility of HS muscle strips significantly (0.79±0.17 vs. 0.40±0.11, P<0.01). But the blocker of ATP-sensitive potassium channel glibenclamide had no effect on the contractility of HS muscle strips (0.47±0.14 vs. 0.40±0.11, P>0.05). Compared with those of control group, iNOS activities (2.295±0.310 U/g vs. 1.319±0.322 U/g) and NO contents (2.880±0.353 μmol/g vs. 1.505±0.387 μmol/g) in duodenum of HS rats were both significantly increased (both P<0.01). Under light microscopy, the most significant morphological change in duodenum following HS was the infiltration of obvious inflammatory cells., Conclusions: The NO produced by the overexpression of iNOS induced by HS involves in the motility dysfunction of intestine through the mechanism of cyclic guanosine monophosphate (cGMP) system. Moreover, NO-mediated infiltration of inflammatory cells in tissue may also contribute to the development of motility dysfunction of intestine following HS.

Objective: To investigate the effects of surfentanyl and fentanyl on spontaneous contractions of isolated uterine smooth muscles of rabbits., Methods: Thirty isolated uterine smooth muscles strips of rabbits with rhythmic spontaneous contraction were randomly divided into three groups: control group (n = 10) fentanyl group (n = 10) and surfentanyl group (n = 10). The effects of fentanyl and surfentanyl on spontaneous contractions intensity, frequency and duration of isolated uterine smooth muscles of rabbits in different concentrationswere monitored., Results: There were no effect on the spontaneous contraction of isolated uterine muscles of rabbits at the concentration of 1 x 10(-8) mol/L in fentanyl group. The spontaneous contraction intensity was decreased significantly when the concentration of fentanyl more than 3 x 10(-8) mol/L (P < 0.05). The spontaneous contraction intensity, frequency and duration was inhibited more than 50% when the concentration of fentanyl more than 3 x 10(-7) mol/L (P < 0.05). And the spontaneous contraction duration was inhibited more than 50% when the concentration of surfentanyl more than 1 x 10(-7) mol/L (P < 0.05). Compared with surfentanyl group, there were significant difference on spontaneous contraction intensity when the concentration of fentanyl more than 3 x 10(-8) mol/L (P < 0.05). Difference on frequency, more than 3 x 10(-8) mol/L (P < 0.05) and difference on duration, at the concentration of 1 x 10(-7) and 1 x 10(-7) mol/L (P < 0.05)., Conclusion: Fentanyl restrained the spontaneous contractions of isolated uterine smooth muscles of rabbits in concentration-dependent manner. Surfentanyl could reduce the spontaneous contractions duration on isolated uterine smooth muscles of rabbits. But there were no effect on frequency and duration.

Objective: To investigate the effect of growth hormone secretagogue(ghrelin) on the contraction and relaxation of small intestinal smooth muscle in rats and its mechanism., Methods: Twenty-four vagotomized rats were injected intraperitoneally with different concentrations of ghrelin (0, 20, 40, 80 μg/kg). The small intestinal transit were observed. The effect of ghrelin(0.01, 0.1, 0.5, 1.0 μmol/L) on the contraction and relaxation of rat small intestinal smooth muscle strips was observed in vitro in the presence of carbachol(50 nmol/L), the locations of ghrelin receptors(GHS-R1a) on different cells in small intestinal muscle layers were detected by immunofluorescence., Results: With the increase of concentrations, ghrelin elevated the percentage of small intestinal transit[(25.4±1.0)%, (33.7±1.9)%, (39.3±2.4)%, (44.7±2.1)%] in a dose-dependent manner, and the differences were statistically significant among groups(P<0.05). Ghrelin could also enhance the contraction [(67.0±2.4)%,(149.5±3.3)%, (187.1±4.7)%, (213.5±3.4)%] and relaxation[(35.3±1.1)%, (62.9±3.8)%, (79.6±2.7)%, (94.6±2.2)%] of smooth muscle strips mediated by Cch in a dose-dependent manner, and the differences were statistically significant among groups(P<0.05). Immunofluorescence revealed that ghrelin receptors mainly located on membrane of the nerve cells in the muscle layers, while no receptors were observed on membrane of the smooth muscle cells., Conclusion: Ghrelin may enhance the effect of the contraction and relaxation of the rat small intestinal smooth muscle mediated by cholinergic neurotransmitters by activating the nerve cells in the enteric plexus.

Objective: To study contractility of guinea pig ileum in vitro,and analyze the mechanism of anti-emetic effects of Lianqiao., Method: Using emesis-relating agonists as drugs, the inhibitory effects of Lianqiao on guinea pig ileum contractility in vitro were observed in organ bath., Result: Lianqiao could inhibit guinea pig ileum spontaneous contractions, reducing the tone of contractions dose-dependently. Acetylcholine (Ach), histamine (His), 5-hydroxytryptamine (5-HT) stimulated contractions of the guinea pig ileum, enhanced the tone and amplitude. All the three doses (10, 5, 2 g x L(-1)) of Lianqiao could suppress the contractility, significantly reduced the tone and amplitude of ileum contractions stimulated by drugs but not the frequency. Dopamine could inhibit the spontaneous contraction tone and amplitude of ileum; Both the large doses (10, 5 g x L(-1)) of Lianqiao could antagonise the inhibitory effect of DA, enhance the tone and amplitude. Small dose(2 g x L(-1)) had additive effects on tone of ileum contractions with DA,but enhanced the amplitude not the frequency., Conclusion: Lianqiao have an inhibitory effect on guinea pig ileum contractions,the mechanism might be blocking M receptor, H1 receptor, 5-HT receptor and D2 receptor or directly suppressed ileum smooth muscle. The mechanisms of anti-emetic effect of Lianqiao needs further study.

Seven sinapine analogs (6a-6g) were synthesized using cinnamon acid or benzoic acid and their derivatives as starting materials, which obtained from substituted benzaldehyde and malonate. The structures of target compounds were characterized by IR, 1H NMR and elemental analysis. The effects of compounds 6a-6g on the smooth muscle of intestine isolated from rabbit were studied, and the experimental results showed that compounds 6a, 6d and 6g had diastolic action, while 6f had contractile action.

Objective: To study the effects of Compound Danshen Dripping Pill (CDDP) on the structure and functions of sternohyoid muscle in metabolic syndrome (MS) rats, and to study whether it has therapeutic effects on obstructive sleep apnea-hypopnea syndrome (OSAHS)., Methods: Twenty-one healthy male SD rats were randomly divided into three groups, i.e., the normal control group (n = 6), the MS group (n = 8), and the CDDP group (n = 7). Rats in the normal control group were routinely fed. High lipid forage was given to rats in the rest two groups. Nine weeks later, CDDP (at the dose of 375 mg/kg) was additionally given to rats in the CDDP group by gastrogavage, and then rats in the CDDP group and the MS group were fed with the same high lipid forage for 12 successive weeks. The content of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) in the sternohyoid muscle were detected in the three groups. The capillary density, capillary-to-fiber ratio (C/F), the section area of type I muscle fiber were detected using myosin-ATPase histochemical assay. The contractile changes of isometric stemohyoid muscles were determined under electric stimulation by different frequencies., Results: The contents of MDA were obviously lower in the CDDP group than in the MS group, while the activities of SOD, the capillary density, C/F, the section area of type I muscle fiber, the tension of stemohyoid muscle at 10 -60 Hz, and the 1-5 min tension percentages of the stemohyoid muscle were higher in the CDDP group than in the MS group (P < 0.05, P < 0.01)., Conclusion: CDDP could improve oxidative stress induced intramuscularly microcirculation disturbance and changes of muscular fiber structures of the upper airway muscles, and elevate their contractile functions, thus possibly contributing to favorable effects on OSAHS.

Objective: To observe the effect of Tiangou Jiangya capsule on isolated rabbit aortic strips, and to discuss its antihypertensive mechanism., Method: The isolated rabbit aortic strips were placed in perfusion baths, and induced to contract by norepinephrine (NE), KCl and CaCl2 respectively, then Tiangou Jiangya capsule extraction was added to observe its effect on the contraction. The effect on intracellular Ca2+ dependent contraction and extracellular Ca2+ dependent contraction induced by NE were also studied., Result: The Tiangou Jiangya capsule (1, 3, 5 g x L(-1)) can reduce the largest contract reaction of aortic strips induced by NE or CaCl2 (P < 0.01). It can reduce both intracellular Ca2+ dependent contraction and extracellular Ca2+ dependent contraction induced by NE (P < 0.01), and the effect on extracellular Ca2+ dependent contraction is more significant. But the Tiangou Jiangya capsule has no significant effect on KCl induced contraction., Conclusion: Tiangou Jiangya capsule can regulate intracellular Ca2+ concentration and help to relax the vascular smooth muscle. The mechanism could be regulating the receptor-operated Ca2+ channel. The effect on extracellular Ca2+ dependent contraction is more obvious than on intracellular Ca2+ dependent contraction induced by NE.

Objective: To investigate of the regulatory effect of Rho-kinase pathway activation on angiotensin II (Ang II)-induced contraction of human airway smooth muscle cells (HASMCs) in vitro., Methods: Cultured primary HASMCs were divided into control group, AngII group, AngII + irbesartan group and AngII + Y-27632 group with corresponding treatment. AngII-induced contraction of HASMCs was evaluated using collagen gel lattices and observed morphologically using immunofluorescence assay. Western Blotting was significantly performed to examine the protein expression of Rho-kinase signal pathway., Results: AngII-induced HASMC contraction was inhibited by treatments with irbesartan and Y-27632 as shown by gel contraction assay (P<0.001). Y-27632 treatment produced a stronger inhibitory effect than irbesartan on the expression of phosphorylated moesin, a substrate of Rho kinase (P<0.05)., Conclusion: AngII induces the contraction of HASMCs partially as a result of activation of Rho-kinase pathway.

Objective: To investigate the effects of Ginkgo biloba extract (GbE) on the activities of energy metabolism enzymes and contraction capacity of diaphragm from type 2 diabetic rats., Methods: Forty SD male rats were randomly divided into normal control group (n=10) and model group (n=30). Type 2 diabetes models were induced by feeding with high-sucrose-high-fat diet and intraperitoneal injecting 25 mg/kg streptozotocin. 20 successful models were rearranged to two groups: diabetic group and GbE treatment group, 10 rats in each. Then the saline and 8 mg/(kg x d) of GbE were respectively intraperitoneal injected, once a day continuously for 8 weeks. Then diaphragm contractility was assessed using Peak twitch tension (Pt), Maximum tetanic tension (P0) and fatigue index (FI) in vitro diaphragm strip preparations. Cytochrome oxidase (CCO), lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in diaphragm were detected and the varieties of diaphragm ultrastructure were observed., Results: Compared with control group, Pt, P0 and FI in diabetic group decreased significantly (P < 0.01); the activity of CCO, LDH and SDH in the tissues was more obviously reduced than those in control group (P < 0.01). The ultrastructure in diabetic group under electron microscope indicated that diaphragm mitochondrions swelled and degenerated. The above changes were inhibited by GbE., Conclusion: GbE can enhance contraction capacity of diaphragm from type 2 diabetic rats by increasing the aerobic oxidation capacity, glycolytic capacity and the function of respiratory chain.

Human rhinoviruses (HRVs) are the causative pathogens in more than half of viral upper respiratory tract infections. Currently, no antiviral agents that are active against HRVs are available for clinical use. Because only higher primates are susceptible to HRVs, the screening of new drug is most commonly based on the cell line model. In this study, isolated rabbit airway smooth muscles (ASM) tissue model has been established, and the airway responsiveness with different treatment has been examined. Relative to control tissues, the maximal constrictor (Tmax) response to ACh increased significantly 150% in ASM inoculated with HRV, and relaxation to isoproterenol has been attenuated to 63%. And the abnormal responsiveness can be inhibited in presence of pretreatment with several new compounds which have been exhibited effective anti-HRV activity on cell lines. The results demonstrate that the established ASM model will be applied to screening the anti-HRVs drugs.

A diagram of motor neuron pool of ventral horn of spinal cord gray matter in toad was first delineated. Different concentrations (1, 0.5, 0.1, 0.01 mol/L) of excitatory amino acid L-Glu or physiological saline (0.65% NaCl) were then microinjected into the motor neuron pool in a urethane-anaesthetized toad. The contraction curve of the gastrocnemius was then recorded by the BL-420 Physiological Signal Recording. We took the maximal tension, the duration of rising phase, the velocity of tension variation, and the duration of descending phase as the parameters to study the characteristic of gastrocnemius contractility. It was found that the gastrocnemius contractility of all the 4 groups was tetanus but differed in degree, especially the maximal tension, and velocity of tension variation. In contrast to physiological saline, gastrocnemius contracted by the stimulation of L-Glu, and the contraction parameter showed dose-effect relationships except for the duration of descending phase, which was caused by the combination rate of L-Glu and the receptor.

Objective: To observe the influences of Panax notoginsenosid(a compound of Chinese Traditional Medicine) on the spontaneous contraction of small intestine smooth muscle of rabbits in vitro and explore the mechanism., Methods: The influences of Panax notoginsenosid on the spontaneous contraction of small intestine in intacted rabbits(male or female) after the isothermal perfuse of small intestine in vitro were observed. Bay K8644 and nitro-L-arginine methylester (L-NAME) were added to the normal Tyrode's solution respectively before Panax notoginsenosid. In the Ca2+ free Tyrode's solution, rynodine was added before Panax notoginsenosid. The mechanism of Panax notoginsenosid was studied., Results: Panax notoginsenosid reduced the amplitude of contraction of small intestine smooth muscle in rabbits in a does-depended manner. Bay K8644 and L-NAME could completely block the inhibition of Panax notoginsenosid on the contraction of small intestine smooth muscle. Panax notoginsenosid inhibited significantly the intracellular calcium-depended contraction induced by rynodine in the Ca2+ free Tyrode's solution., Conclusion: Panax notoginsenosid inhibits significantly the contraction of small intestine smooth muscle of rabbits in vitro. The mechanism may be related to increase NO concentration in small intestine smooth muscle so that inhibit extracellular Ca2+ inflowing via cell membrane and intracellular Ca2+ releasing via sarcoplasmic reticulum.

Objective: To investigate the mechanism behind the inhibitive effect of somatostatin (SST) on the intestinal migrating contraction in vivo by observing the effect of SST on spontaneous contractions of the circular muscle of the isolated small intestine and visualizing SST and SST receptor 2 (SSTR2) in the intestinal muscle., Methods: Transverse segments of macaque intestine from laparotomy, were mounted in a perfusion system. The effects of SST on their phasic contractions were recorded. SST and SSTR2 in the intestinal muscles of macaque were visualized by immunohistochemical staining and hybridization in situ., Results: SST (1 x 10(-7) mol/L to 1 x 10(-4) mol/L) significantly increased the frequency of phasic contractions, in a dose-dependent manner, r = 0.984, P < 0.05; (8.33 +/- 1.53) times/min (SST 1 x 10(-7) mol/L) vs (2.67 +/- 0.58) times/min (blank control), P < 0.05. The contractive amplitudes of the isolated circular muscle were also enhanced with the increasing concentration of SST range from 1 x 10(-7) mol/L to 1 x 10(-5) mol/L, r = 0.991, P < 0.05. Both SST and SSTR2 were localized in myenteric nerve plexus between the longitudinal and the circular muscle of the macaque intestine., Conclusions: SST directly promoted spontaneous contractions of the circular muscle of macaque intestine via mediation of SSTR2 in myenteric nerve plexus between the longitudinal and the circular muscle. It is contributed to the inhibitive effect of SST on the intestinal migrating contractions.

Objective: To study the relationship between the inhibitory effects of Tongxie Yaofang, a compound traditional Chinese herbal medicine, on the contraction of the colonic smooth muscle isolated from rats and calcium mobilization., Methods: By measuring the tension of the isolated colonic smooth muscle strips, the inhibitory effects of Tongxie Yaofang on the contraction induced by acetylcholine (ACh), KCl and exhausting Ca(2+) of internal calcium store were assessed respectively., Results: Tongxie Yaofang could concentration-dependently inhibit the contraction of isolated rat colonic smooth muscle strips induced by KCl and exhausting the Ca(2+) of internal calcium store. Tongxie Yaofang could also inhibit the tension of the second contractile phase induced by ACh (P<0.01, vs control), but had no influence on the first contractile phase., Conclusion: Tongxie Yaofang can inhibit the contraction of isolated rat colonic smooth muscle strips mainly by preventing the influx of extracellular Ca(2+), which may be associated with blocking voltage-dependent channel, store-operated channel and receptor-operated channel, but not by preventing the release of internal Ca(2+) from calcium store.

Objective: To observe the effect of alcohol extracts from orientivne and its effective component sinomenine on withdrawal syndromes and neurotransmitter of morphine-abstinent mice and on intracellular calcium level in morphine-dependent neuronal-cells line. To study the detoxification of alcohol extracts from orientvine and sinomenine on morphine-dependent animal and explore the mechanism of its effect., Methods: The effect of alcohol extracts from orientivne and sinomenineon on abstinent syndromes was observed by experiment study on morphine-dependent ex vivo ileum from guinea pigs and morphine-dependent mice. The morphine-dependent model mice were established by injection on dosage increasing by degrees. The hypothalamic monomine neurotransmitters such as NA, DA, 5-HT were tested by fluorospectrophotometry. Morphine-dependent cell line was established by administering morphine at different doses into the culture medium. The cells were stained with fluo-3 and the intracellular calcium level was measured by flow cytometry., Results: Alcohol extracts from orientvine and sinomenine could alleviate withdrawal contractile response of morphine-dependent ex vivo ileum from guinea pigs and withdrawal syndromes of morphine-dependent mice, decrease the concentration of the neurotransmitters, and elevate the intracellular calcium level and inhibit the decreasing of Ca2+ induced by naloxone., Conclusions: Alcohol extracts from orientvine and sinomenine have some effects on withdrawal syndromes which may be related to inhibiting neurotransmitters and the regulation of intracellular calcium concentration.

Aim: To investigate the effect of Honeysuckle flower (HF) and Scutellaria Baicalensis Georgi (SBG) on contraction and electric activity of small intestine smooth muscle in rabbit and the underlying mechanisms., Methods: Using organ bath technique to observe the effect of HF and SBG on contractive and electric activity of small intestine smooth muscle in rabbit., Results: HF and SBG significantly decreased the amplitude, frequency and area under the curve of contractive, as well as electric activity in a dose-depended manner. IC50 of the contractive amplitude was 6.30 g/L and 1.56 g/L by Logit Loglinear analysis. The inhibitive effect of HF and SBG on contractive activity could be partly decreased by beta-receptor blocker Propranolol, NO synthase inhibitor L-NAME, and K+ channel blocker Glibenclamide. Also HF and SBG inhibited acetylcholine-induced both intracellular and extracellular calcium-depended contraction significantly., Conclusion: HF and SBG obviously inhibit the contractive and electric activity of small intestine smooth muscle of rabbit. The mechanisms are related to several pathways.

This study is to observe the difference in pharmacological characteristics between circular smooth muscles of rat isolated gastric body and gastric fundus, and to investigate the effects of nucleoside and nucleotide on circular smooth muscle of the rat gastric body and the involved receptors. Circular muscle strips of the rat gastric body and gastric fundus were prepared, and contractile responses to agonists were investigated with a technique of drug-receptor interaction in functional system. There was no significant difference between the circular muscle strips of the gastric body and gastric fundus in the responses to KCl, and no difference in EC50 values of contractile responses for 5-HT and His between the two kinds of preparations (P > 0.05). However, Emax values of contractile responses to 5-HT and His [(0.81 +/- 0.26) and (0.88 +/- 0.27) g] in gastric body were significantly smaller than those in gastric fundus [(2.67 +/- 0.61) and (1.90 +/- 0.68) g, P < 0.01], and EC50 value of CCh produced contractile response [(0.45 +/- 0.15) micromol x L(-1)] in gastric body was significantly higher than that in gastric fundus [(0.20 +/- 0.09) micromol x L(-1), P < 0.01]. In precontracted circular muscle strips of the gastric body, ATP (0.1-3000 micromol x L(-1)) produced only a contractile response concentration-dependently, but the same concentration of ATP induced a biphasic response (relaxation followed by a contraction) in precontracted circular muscle strips of the gastric fundus. ATP, UTP, ADP, 2-MeSATP and alpha,beta-MeATP produced contractile responses concentration-dependently in circular muscle strips of the rat gastric body. The EC50 value for 2-MeSATP [(7.2 +/- 5.2) nmol x L(-1)] was about 500 times lower than that for Ach [(3.47 +/- 1.20) micromol x L(-1)]. The rank order of potency for the contraction was 2-MeSATP>>ADP>ATP=UTP>alpha,beta-MeATP>>adenosine. The contractile responses to ATP and UTP were not significantly affected by phentolamine, propranolol, atropine or tetrodotoxin. In conclusion, there is a significant difference in pharmacological characteristics between the circular smooth muscles of the rat gastric body and gastric fundus and nucleotides might be important mediators responsible for the contraction via a specific P2Y receptor in circular smooth muscle of the rat gastric body.

Objective: To study the kinetogenic effects of serum containing Semen Arecae, Dandelion, Semen raphani and Atractylodes macrocephala on the colonic smooth muscle cells of rats., Methods: Serum containing Chinese materia medicas was made according to standard methods. Smooth muscle cells were isolated from the muscle layers of Wistar rat's colon, referred to modified Bitar's method. The contractile response of colonic smooth muscle cells to serum containing Chinese materia medicas (10%, 50%, 100% concentration) and other medicines (blank and 1 x 10(-3) mol/L acetylcholine) were separately observed. The contractility was presented by the decrease of the cell length between the drug groups and the control., Results: Serum containing each Chinese materia medica can make dose-dependent contraction at different concentrations (P < 0.05), but the strongest effect of each serum had no significant difference (P > 0.05)., Conclusion: Serum containing Semen Arecae, Dandelion, Semen raphani and Atractylodes macrocephala can make notable contraction on colonic smooth muscle cells in rats.

Objective: To observe the antitussive and antiasthmatic effects of Radix Fici Hirtae (RFH)., Methods: Antitussive effects were observed by ammonia water steaming test in mice and by citric acid test in guinea pigs. Antiasthmatic actions in guinea pigs were observed by histamine and acetylcholine ultrasonic atomization test, involved isolated guinea pig tracheal smoth muscle experiment and anaphylactic shock of guinea pigs., Results: RFH decreased the frequency of cough induced by ammonia in mice and by citric acid in guinea pig, prolonged the latent period of cough and inhibited the experimental asthma by histamine and acetylcholine solution in conscious guinea pigs, antagonisted the contraction of tracheal smooth muscle by histamine phosphate in guinea pigs and could compete anaphylactic shock in guinea pigs., Conclusion: RFH has obvious antitussive and antiasthmatic effects.

Objective: To study the effect of Ning Wei Kang Recipe extract on gastrointestinal motor function., Methods: The effects of Ning Wei Kang Recipe extract on gastrointestinal motor function were studied in mice, rabbits, and isolated mesenterial intestines of guinea pig according to its effect on acetylcholine or barium chloride-induced contraction., Results: Ning Wei Kang Recipe extract could significantly decrease the propellent movement of medicine charcoal in the mesenterial intestine of mice (P < 0.01), inhibit the range and speed of mesenterial intestine of rabbits (P < 0.05, or P < 0.01), relax the contration of isolated mesenterial intestines of guinea pig induced by BaCl2 (P < 0.05). But it could not decrease the contration of isolated mesenterial intestines of guinea pig induced by acetylcholine (P< 0.05)., Conclusions: Ning Wei Kang Recipe extract can significantly inhibit the gastrointestinal motor function. It may be related to blocking positive ion-Ba2+ into gastrointestinal smooth muscle cell.

Objective: To identify and elucidate the vasorelaxant activity of homoisoflavonoids, the main chemical components from Lignum Sappan (the stems of Caesalpinia sappan), in isolated rat thoracic aortic rings pre-contracted with phenylephrine (PE, 1 micromol x L(-1)) and KCl (60 mmol x L(-1))., Method: The tension of rat thoracic aorta rings was used to evaluated the vasorelaxant activities of four homoisoflavonoids, brazlin (1), (E)-3-(3,4-dihydroxybenzylidene)-7-hydroxychroman-4-one (2), sappanone B (3), 3-deoxysappanone B (4)., Result: Cumulative addition of homoisoflavonoids (2, 3 and 4) (50-1000 micromol x L(-1)) exhibited an acute relaxation either in endothelium-intact or endothelium-denuded rings in a concentration-dependent manner. However, this relaxation was significantly inhibited in endothelium-denuded condition and in the presence of endothelial nitric oxide synthase (eNOS) inhibitor, N(W)-nitro-L-arginine methyl ester (L-NNA, 100 micromol x L(-1)), and a soluble guanylate cylcase (sGC) inhibitor, methylene blue (MB, 10 micromol x L(-1)) when addition of variation homoisoflavonoids brazlin (1) (50-1000 micromol x L(-1))., Conclusion: These results indicate that normo-homoisoflavonoids (2, 3 and 4) from Caesalpinia sappan mediates endothelium-independent vasodilator action in rat thoracic aortic rings, while the variation homoisoflavonoids brazlin elicits endothelium-dependent relaxation might via nitric oxide (NO)-cGMP pathway. This research could explain the pharmacological activities of homoisoflavonoids to a certain degree.

Objective: To investigate the effect of isopropyl 3-(3,4-dihydroxyphenyl)-2- hydroxypropanoate on vascular smooth muscle., Method: Isolated rat pulmonary artery was perfused and the tension of the vessel was measured, the effect of isopropyl 3-(3, 4-dihydroxyphenyl)-2-hydroxypropanoate on the pulmonary artery precontracted by noradrenaline (NE) and concentration-response curves of 5-hydroxytryptamine (5-HT), endothelin-1 (ET-1), U46619 and KCl was also observed., Result: Isopropyl 3-(3,4-dihydroxyphenyl) -2-hydroxypropanoate exerted relaxation effect on the endothelium-intact artery precontracted by NE in a concentration-dependent manner, which was inhibited with denuded endothelium. The right-shift of the concentration-response curves of 5-HT, ET-1, U46619 and KCl., Conclusion: Isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate have relaxation action on rat pulmonary artery in the way of endothelium-dependance, the mechanism of relaxation action by isopropyl 3-(3,4-dihydroxyphenyl) -2-hydroxypropanoate may be related to calcium channels.

Objective: To study the spasmolysisy activity constituents of the Radix Paeoniae alba and Radix et Rhizoma compound., Method: The three effective compounds of Radix Paeoniae and Radix et Rhizoma were arrayed to eight groups by orthogonal design rat, serum samples were collected after administered in these groups, and these serum samples were used to carry out the experiments of serum pharmacology of spasmolysis. The inhibition ratios were assigned as pharmacodynamic variable X, the areas of characteristic peaks on HPLC fingerprints were assigned as variable Y, and the correlation of X and Y was studied in order to research the activity spasmolysisy compounds of effective constituents. Serum samples were analyzed by HPLC-ESI-MS/MS., Result: The correlation of fingerprints and pharmacology showed that four compounds were the main spasmolysisy activity compounds. The correlation parameter was greater than >0.4, whose value were 0.774, 0.678, 0.566 and 0.472 respectively, and their retention times were 8.03, 51.7, 54.59 and 72.43 min respectively. They were metabolites of effective compounds., Conclusion: This study makes a valid approach for understanding the material foundation of TCM by establishing the correlation of fingerprints and pharmacology of activity compounds in vivo.

Objective: To study the vasodilation effect of the procyanidin (PC) extracted from grape seeds on rabbit thoracic aortic rings in vitro, decreasing blood pressure in vivo and the possible mechanism., Method: Rabbits aortic rings were isolated and were divided into six groups including removal of endothelium, integrity of endothelium, 1 x 10(-5) mol X L(-1) indomethacin (Indo), 1 x 10(-5) mol x L(-1) propranolol (Prop), 1 x 10(-4) mol x L(-1) N(omega)-nitro-L-arginine (L-NNA) and 1 x 10(-5) mol x L(-1) methylene blue (MB). Then the thoracic aortic rings were treated with PC with cumulative concentrations of 1.25, 2.5, 5.0 mg x L(-1) respectively and the changes of tension were recorded, and investigate the effect of 40 mg x L(-1) PC on the contraction of aortic smooth muscles, thoracic aortic rings were pre-treated with NA (1 x 10(-8) to approximately 1 x 10(-5) mol x L(-1)), KCl (6.3 to approximately 100 mmol x L(-1)) and CaCl2 (1 x 10(-5) to approximately 1 x 10(-5) mol x L(-1)) followed by treatment with PC. Then, rabbits common carotid artery was intubated and arterial blood pressure in vivo was recorded. PC with cumulative concentrations of 4.0, 8.0, 16, 32, 64, 84 mg x kg(-1) was injected into vein and the changes of arterial blood pressure were observed., Result: PC could relax isolated rabbit aorta and showedan obvious concentration-dependent relaxation (r = 0. 63, P < 0.001). The relaxant effect of PC was significantly reduced by removal of endothelium and by treatment with nitric oxide synthase inhibitor L-NNA, or guanylyl cyclase inhibitor MB. In addition PC could decrease the dose response curves of aortic rings to NA, KCl and CaCl2. PC has a significant concentration-dependent negative effect on arterial blood pressure in vivo (r = 0.92, P < 0.001)., Conclusion: PC has a vasodilation effect not only in an endothelium-dependent, nitric oxide involved manner, but in inhibition of calcium release and blockage of potential-dependent calcium channels. PC could decrease the rabbit's arterial blood pressure significantly in vivo.

Objective: To investigate the diaphragmatic contractile function and mitochondrial ultrastructure in rats with acute lung injury., Methods: Twenty-eight Sprague-Dawley (SD) rats were allocated randomly into three groups: a control group (n = 10), a lipopolysaccharide (LPS, endotoxins) 4 h group (n =9) and aLPS 24 h group (n =9). Diaphragmatic samples were taken at 4 h and 24 h after 100 microg/kg LPS was instilled into the trachea of the rats. Normal saline (0.5 ml/kg) was instilled in the control group. Then the contractile function of the diaphragmatic samples, including the peak twitch tension, frequency depended force and fatigue index (FI), was tested in vitro. The diaphragmatic ultrastructure was also measured by electron microscopy. SPSS version 15.0 was used for statistical analysis. Data were presented as x +/- s, and means were compared with analysis of variance., Results: The diaphragmatic force-generating capacity and peak twitch tension in LPS4 h group [(3.4 +/- 1.9); (0.9 +/- 0.4) N/cm2 ] decreased significantly compared to the control group [(6.7 +/- 4.3); (2.2 +/- 1.7) N/cm2, F = 3.59 and 3.78 respectively, P <0.05], but a marked recovery was observed in LPS 24 h group [(4.1 +/- 1.2) and (1.2 +/- 0.7) N/cm), P <0.05]. The FI was also reduced remarkably in LPS 4 h and LPS 24 h adL group (0.07 +/- 0.06; 0.12 +/- 0.07) compared to the control group (0.26 +/- 0.14, F = 9.27, P < 0.01. Ultrastructural examination showed mitochondria derangement at LPS 4 h and LPS 24 h groups, including swollen mitochondria with abnormal cristae, and disrupted external membrane of mitochondria., Conclusion: Diaphragmatic contractile force-generating capacity decreased remarkably in rats treated with 100 microg/kg LPS, and the diaphragm was susceptible to developing fatigue. These changes may result in respiratory failure.

Objective: To investigate the alterations in structure and function of sternohyoid muscle of metabolic syndrome (MS) rats effects and the effects of taurine thereupon contractile properties., Methods: Twenty-one healthy male SD rats were randomly assigned to three groups: control group (Group A, n=6) fed with normal food, MS group (Group B, n=8) fed with high-lipid forage for 9 weeks to induce MS and then fed with the same high-lipid forage for 12 weeks in addition, and taurine group (Group C, n=7), fed with high-lipid forage for 20 weeks and given gastric perfusion of taurine 50 mg x d(-1) x kg(-1) since the tenth week for 12 weeks. Venous blood samples were collected to undergo biochemical examination of plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and glucose (Glu). Radioimmunoassay was used to detect the plasma insulin. The sternohyoid muscles were collected. Muscle tissue homogenate was made. The superoxide dismutase (SOD) and malondialdehy (MDA) levels were measured. Myosin-ATPase histochemistry was used to assay the size and capillary density of the isolated sternohyoid muscles. Isometric contractile properties were determined by electrostimulating the strips of isolated sternohyoid muscles at different frequencies (from 10 Hz to 100 Hz) to observe the changes of the sternohyoid contractile properties in different conditions., Results: (1) The levels of TG, LDL, Glu, PGI, and MDA of Group B were significantly higher than those of Groups A and C, while the HDL level of Group B was significantly lower than that of Group A (P < 0.01). The OD level of Group B was significantly lower than those of Groups A and C. (2) The capillary density, capillary-to-fiber ratio (C/F), and cross-sectional area of type I fiber in sternohyoid muscles of Group B were (140 +/- 5)/ nm2, 0.90 +/- 0.11, and (6119 +/- 165) microm2 respectively, all significantly higher than those of Group A [(278 +/- 17)/mm2, 1.43 +/- 0.05, and (9371 +/- 68) microm2 respectively, all P < 0.01] and Group C [(269 +/- 10)/mm2, 1.40 +/- 0.07, and (9007 +/- 136) microm2 respectively, all P < 0.01]. (3) The tensions of sternohyoid muscle of Group B at the frequencies from 10 Hz to 60 Hz were (29 +/- 6) g/cm2, (34 +/- 7) g/ cm2, (41 +/- 6)g/cm2, (47 +/- 6)g/cm2, (53 +/- 7)g/cm2, and (59 +/- 20)g/cm2 respectively, all significantly lower than those of Group A group[(40 +/- 3)g/cm2, (52 +/- 13)g/cm2, (60 +/- 17) g/cm2, (74 +/- 32) g/cm2, (80 +/- 29)g/cm2, and (96 +/- 24)g/cm2 respectively, all P < 0.05] and Group C [(43 +/- 26)g/cm2, (48 +/- 6)g/cm2,(55 +/- 9)g/cm2, (67 +/- 14)g/cm2, (75 +/- 15)g/cm2, and (80 +/- 15)g/cm2 respectively, all P < 0.05]. (4) In fatigue test, the tension percentages of sternohyoid muscle at the time intervals of 1 min, 2 min, 3 min, 4 min, and 5 min of Group B were (80.5 +/- 8.0)%, (64.1 +/- 1.2)%, (59.1 +/- 1.1)%, (56.4 +/- 10.9)%, and (53.5 +/- 9.1)% respectively, all significantly lower than those of Group A [(87.7 +/- 3.5)%, (78.5 +/- 1.5)%, (76.0 +/- 1.2)%, (72.3 +/- 15.0)%, and (68.7 +/- 17.2)% respectively, all P < 0.05] and Group C group [(87.4 +/- 2.4)%, (77.9 +/- 5.5)%, (73.6 +/- 1.1)%, (71.3 +/- 8.7)%, and (68.0 +/- 6.7) respectively, all P < 0.05]., Conclusion: With the development of MS, the capillary density, C/F, cross-sectional area of type I fiber of upper airway muscles decrease, in part via oxidative stress, which leads to reduction of the contractile function of upper airway muscles, thus contributing to the onset of obstructive sleep apnea-hypopnea syndrome.

Objective: To investigate the effect of morphine chloride on small intestinal muscle in vitro or in vivo and its mechanisms., Methods: Contractile amplitude, tension and frequency of the isolated small intestine of rabbits were measured before and after treatment of morphine chloride. The propulsive distance of magenta in intestinal tract was measured when different concentration of morphine chloride was given orally in mice., Result: After treatment of different concentration of morphine chloride (5 mg/L, 10 mg/L, 30 mg/L), the contractile activities of isolated small intestines of rabbits decreased significantly. The inhibitory effect of morphine chloride was blocked by naloxone, atropine, but potentiated by regitine. The propulsive distance of magenta in intestinal tract of intact mouse decreased after treatment with morphine chloride of various concentration (75, 150, 300 mg/L)., Conclusion: Morphine chloride has an inhibitory effect on the contractility of rabbit small intestine in vitro or in vivo. Opioid receptor, choline and adrenal receptor might be involved in this effect.

Objective: To investigate the effects of Wujiwan extracts in two different compatibility proportions (named the No. 1 and No. 2 respectively) on motility of isolated colon in guinea pig, and compare the therapeutic effects with each other., Method: To observe the function of the No. 1 and No. 2 with different concentrations on colon contraction induced by acetylcholine (Ach) and inhibition induced by adrenalin (Ad) respectively, and calculate the EC, with the method of Bliss., Result: The No. 1 and No. 2 both could significantly inhibit the contraction of colon, and in 15 minutes, there was significant time-dependence and concentration-dependence, and EC50 of the No. 1 was lower than that of No. 2. However, but when the colonic was inhibited by Ad, at the time of 9 min and 15 min, the No. 1 at the level of 300 mg x L(-1), and at the time of 15 min, the No. 2 at the level of 30 mg x L(-1), could both excite the colon significantly (P < 0. 05)., Conclusion: Our experiments indicate that the No. 1 and No. 2 both can significantly inhibit the colon contraction in guinea pig, and the No. 1 is superior to the No. 2 to some extent. And at the same time, we also can conclude that the No. 1 and No. 2 have exciting effects on inhibitory colon. Meanwhile, the No. 1 and No. 2 each have its own advantages based on the common therapeutic effects.

Objective: To observe effects of Fufang Xiaojingtong capsules (FXJTC) on activities of the uterine smooth muscle of the rat in vitro and the uterus of the rabbit in vivo., Method: The isolated rat uterine smooth muscle strips were mounted in a Magnus bath containing Locke's solution with a final content of 12.48, 6.24 or 3.12 mg x mL(-1) of FXJTC at 37 degrees C; and 2.0, 1.0 and 0.5 g x kg(-1) of FXJTC and 2.0 g x kg(-1) of Tianqi Tongjing capsules were respectively given to the rabbits through the duodenum, respectively. Their effects on frequency, amplitude and activity of contraction of the rat uterus in vitro and the rabbit uterus in vivo were investigated., Result: FXJTC could significantly inhibit the frequency, amplitude and activity of contraction of the normal rat uterus in vitro and decrease the oxytocin-induced increase of contraction of the rabbit uterus in vitro; lowered the frequency, amplitude and activity of contraction of the rabbit uterus in vivo and inhibit the oxytocin-induced the strengthening of contraction of the rabbit uterus in vivo., Conclusion: Fufang Xiaojingtong capsules maybe used for treatment of dysmenorrhea induced by spasm of uterine smooth muscle.

Objective: To study the effects of sulfated cholecystokinin octapeptide (sCCK-8S) on intracellular calcium release and extracellular calcium influx in gastric antral smooth muscle cells (SMC) and the mechanism thereof., Methods: (1) Longitudinal muscle (LM) and circular muscle (CM) strips of gastric antrum and pylorus were isolated from SD rats and suspended in a tissue chamber to record the contractile responses by polyphysiography. (2) Immunoprecipitation, electrophoresis, and immunoblotting were used to detect the phosphorylation of type III inositol 1, 4, 5-triphosphate receptor (InsP(3)R(3)) in the SMCs. (3) The responsiveness of gastric SMC to CCK-8S was examined by using fura-2-loaded microfluorimetric measurement of intracellular calcium concentration ([Ca(2+)]i). (4) The current of L-type calcium channels (ICaL) was recorded by using patch-clamp techniques., Results: (1) Significant changes to CCK-8S were found in the mean contractile amplitude of the CM and frequency of LM of gastric antrum and could be suppressed by CCK-A receptor (CCK-AR) antagonist and ATPase inhibitors. (2) CCK-8S stimulation of SMC resulted in PKC-dependent phosphorylation of the InsP(3)R(3). (3) CCK-8S-evoked significant increase in [Ca(2+)]i [from (69 +/- 7) mol/L to (472 +/- 36) nmol/L, P < 0.01] could be suppressed by CCK-AR antagonist, ATPase inhibitors and protein kinase C (PKC) activator; whereas on condition that extracellular calcium was removed or L-type calcium inhibitor nifedipine was added a small but significant increase of [Ca(2+)]i could be still elicited by CCK-8S. (4) CCK-8S-intensified calcium current [from (-56 +/- 7) pA to (-89 +/- 6) pA, P < 0.01] could be apparently inhibited by respective administration of nifedipine, ATPase inhibitors, and calcium dependent chloride channel (I(Cl-Ca)) blocker (all P < 0.01)., Conclusion: CCK-8S-evoked [Ca(2+)]i increase in gastric antral SMCs depends on the release of intracellular calcium stores, which is regulated by PKC mediated phosphorylation of InsP(3)R(3). The released intracellular calcium in turn activates the L-type voltage-dependent calcium channels (VDCC) through the activation of calcium dependent chloride channels, and ultimately results in the occurrence of contraction response of smooth muscles.

Objective: To evaluate the effects of recombined human Neuregulin on the contractibility of cardiac muscles of Rhesus Monkeys with pacing-induced heart failure and to reveal the possible mechanisms involved., Methods: Twenty four rhesus monkeys were randomly divided into three groups (shame operated group, heart failure group and Neuregulin treated group), each with 8 monkeys. Heart failures were induced by rapid pacing (240 heartbeats/min). Daily intravenous injection of recombined human Neuregulin [3 microg/(kg x d)] and medical salt fluid were given to the monkeys for 10 days for the Neuregulin treated group and heart failure group respectively. Hemodynamic measurements such as peak positive rate of change in left ventricular blood pressure (+dP/dtmax) and left ventricular systolic, and end-diastolic blood pressures (LVSP and LVEDP) were compared between groups. The real-time quantitative RT-PCR was undertaken to detect the expression of myosin heavy chain mRNA in the left ventricular cardiac muscle., Results: The monkeys in the heart failure group had lower levels of +dP/dtmax and LVSP and higher levels of LVEDP than those in the shame operated group (P < 0.05). The monkeys in the Neuregulin treated group had higher levels of + dP/dtmax than those in the heart failure group (P < 0.05). Lower expression of alpha-myosin heavy chain mRNA in the heart failure group was found compared with the shame operated group and Neuregulin treated group (P < 0.05)., Conclusion: Recombined human Neuregulin can enhance the contractibility of cardiac muscles and relieve heart failure syndrome through reversing the falling of alpha-myosin heavy chain induced by rapid ventricular pacing.

Objective: To study the mechanism of herbal application along meridians for treatment and prevention of asthma by using serum pharmacological test to observe the effects of serum containing herbs against the constriction of tracheal spiral strips induced by acetylcholine chloride (Ach)., Methods: Guinea pigs were randomly divided into normal control group, normal saline (NS) application group, aminophylline application group, aminophylline injection group, 1-day herb application group, 7-day herb application group and 14-day herb application group. Asthma was induced by Hutson's method in guinea pigs except the normal control group. Guinea pigs in herb application groups were treated by external application of a compound herbal medicine 60 min once every day. Guinea pigs in NS application group were treated by external application of NS. Guinea pigs in the two aminophylline-treated groups were treated by external application and intraperitoneal injection of aminophylline at a dose of 400 mg/kg, respectively. The guinea pigs were killed and the sera were obtained after 1-day, 7-day and 14-day treatment in the three herb application groups, 7-day treatment in the NS application group, the aminophylline application and injection groups, respectively. Serum pharmacological method was used to do the experiment, the effects of different sera on the constriction of tracheal strips were observed, and the constriction rates were calculated., Result: The serum containing herbs had an effect in reducing the constriction of tracheal spiral strips induced by Ach, and the effect was similar to that of the serum obtained from the aminophylline injection group. The constriction rate of the tracheal spiral strips was decreased when herbal application treatment was prolonged within a period of time, and it became stable when herbal application treatment was between 7-14 days. The constriction of tracheal spiral strips induced by Ach could be reduced remarkably when it was previously treated by serum containing herbs., Conclusion: The anti-acetylcholine function with a time-dependent effect is one of the mechanisms of herbal application treatment along meridians for asthma, and furthermore, herbal application treatment along meridians might be useful for preventing asthma.

Objective: To investigate the mechanism of estrogen action on bladder., Methods: By examining the functional, histological and ultrastructural changes that occurred in the bladder of rats with estrogen depletion and supplementation, we studied the actions of estrogen on bladder. A total of 30 female adult Sprague-Dawley rats were divided into 3 groups, including control group, bilateral ovariectomy (OVX) group and bilateral ovariectomy plus estradiol valerate (OVX + E) group. After medication for 12 weeks, cystometry was performed. Masson stain was used to quantify the area densities of collagen fiber and smooth muscle and their ratios, and electron microscopy was used to evaluate ultrastructure of detrusor muscle., Results: In OVX group, bladder maximal capacity, (0.32 +/- 0.20) ml, compliance, (0.012 +/- 0.006) ml/cm H2O (1 cm H2O = 0.098 kPa), and maximal contraction force, (1.4 +/- 0.4) cm H2O were obviously lower than those in control group, which were (1.11 +/- 0.09) ml, (0.026 +/- 0.003) ml/cm H2O, and (4.4 +/- 0.3) cm H2O, respectively (P < 0.05). In OVX + E group, bladder maximal capacity (0.83 +/- 0.10) ml was lower than that in control group (P < 0.05), but compliance, (0.029 +/- 0.003) ml/cm H2O and maximal contraction force, (4.8 +/- 1.4) cm H2O were similar to those of control group (P > 0.05). Collagen fiber area density and collagen fiber to smooth muscle area density ratio in OVX group (0.218 +/- 0.041 and 0.54 +/- 0.08) were higher than those in control group (0.160 +/- 0.039 and 0.32 +/- 0.09, P < 0.05); however, there were no significant differences between OVX + E group (0.178 +/- 0.027, 038 +/- 0.06) and control group (P > 0.05). In OVX group, ultrastructure of detrusor muscle showed degenerative change, while it was not found in the other groups., Conclusions: When the rat was ovariectomized, bladder function became poor and supplementary estrogen could improve bladder function. This effect may be due to inhibition of collagen hyperplasia and protection of cell organelles. Estrogen replacement should be beneficial for treating postmenopausal lower urinary tract symptoms.

Objective: To observe vasodilation effect of EUL and its mechanism., Method: Isometric tension was recorded in isolated rat thoracic artery precontracted by noradrenaline (NE) to study the vasodilation effect of EUL, and to investigate the role of endothelial cell and vascular smooth muscle cell on vasodilation., Result: EUL was shown to significantly relax the endothelium-intact arteries precontracted by NE, relaxation had fall down on endothelium-denuded arteries. EUL did not affect the concentration-contraction curve of K+. NE and CaCl2 to shift to the right with an decrease in the maximum effective response, manifesting non-competitive antagonism (P <0. 01). The relaxant effect of EUL was significantly inhibited by pretreatment of endothelium-denuded aorta with potassium channel antagonist glibenclamide., Conclusion: EUL induces relaxation in rat aortic rings. The mechanisms may involve the endothelium and the activation of the potassium channels.

Aim: To investigate the hypersensitization of alpha-adrenoreceptor of artery smooth muscle in hypertensive patients and rats and the mechanisms concerned., Methods: Isometric tension of artery ring segments was recorded by a sensitive myograph system in vitro and the relative amount of alpha-adrenoreceptor mRNA was quantified by a real-time PCR., Results: Noradrenaline (NA)-induced concentration-contraction curve of mesenteric artery segments in spontaneously hypertensive rats (SHR) was more potent than that in Wistar-Kyoto (WKY) rats. The E(max) of NA in SHR was 1.82 times of that of WKY. The concentration-contractile curve induced by NA in great omental arteries of hypertensives significantly shifted toward left and the pD2 value of NA was larger than that of normotensives. After organ culture, the concentration-contractile curves of SD rat mesenteric artery induced by NA shifted toward left with significantly increased E(max). The relative amounts of mRNA for alpha1-adrenoreceptor was increased, but mRNA level for alpha2-adrenoreceptor did not change., Conclusion: The sensitivity of alpha1-adrenoreceptor of artery smooth muscle in hypertensive man and rat is enhanced, suggesting alpha1-adrenoreceptor is upregulated.

Objective: To study the mechanism of relaxation of gastrointestinal smooth muscles by vitamin K(3)., Methods: Stripes of proximal colon were collected from guinea pigs. Suspension of single cells was created from these stripes. TD-112S transducer was used to measure the contraction of the stripes stimulated by vitamin K(3) of the concentrations of 40, 100, 400, and 800 micromol/L respectively. The Ca(2+)-activated K(+) current [IK(Ca)] of the cytomembrane of the colon smooth muscle was recorded with an EPC 10 amplifier under conventional whole cell patterns., Results: The contraction frequencies of the muscle stripes stimulated by vitamin K(3) of the concentrations of 40, 100, 400, and 800 micromol/L were 79% +/- 4%, 58% +/- 5%, 33% +/- 4%, and 12% +/- 3% respectively of that of the control group (all P < 0.01), and the contraction strength was reduced to 77% +/- 10%, 54% +/- 7%, 30% +/- 6%, and 11% +/- 4% respectively (all P < 0.01). The IK((Ca)) of the cytomembrane of the colon smooth muscle at the voltage of +60 mV was increased to 120% +/- 18%, 149% +/- 12%, 197% +/- 19%, and 223% +/- 14% respectively (all P < 0.01)., Conclusion: Vitamin K(3) inhibits the contractile activity of the colonic muscle stripes and increases the IK(Ca) of single myocytes concentration-dependently. The mechanism is activation of the Ca(2+)-activated K(+) channel, thus promoting the potassium efflux.

Aim: To search for some substituted alpha-amino phosphonates as leading compounds with the vasodilator effects., Methods: Target compounds were prepared from benzyl aldehyde, piperazine and diethyl phosphite using alcohol as solvent via Mannich-type reaction. In isolated rat aorta and in isolated guinea pig ileum, the vasodilator effects of compounds were investigated and evaluated whether they activated muscarine receptor., Results: Seven compounds of substituted alpha-amino phosphonates have been synthesized and identified by IR, 1H NMR and elemental analysis. Three of them, compound 2a, 2b and 2c have vasodilator activity and do not activate M receptor., Conclusion: Two (2b and 2c) of them were found to have the notable vasodilator effect, and the rates of relaxing are (67 +/- 21) % and (82 +/- 18)%, separately. But they did not activate M receptors on ileum.