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Objective: To explore the effects of Angiotensin (ANG)-(1-7) on postangioplasty fibrotic remodeling and the involvement of TGF-beta/Smad signaling pathway in this process., Methods: Thirty two healthy New Zealand white rabbits were randomly divided into 4 groups: sham group, control group, ANG-(1-7) group and ANG-(1-7) + A-779 group. Rabbits underwent angioplasty in the abdominal aorta or sham surgery. Subsequently, an osmotic minipump was implanted for saline, ANG-(1-7) (576 microg x kg(-1) x d(-1)) or ANG-(1-7) + A-779 (576 microg x kg(-1) x d(-1)) delivery. Before and after 4 weeks treatment, the levels of ANG II in plasma were measured by ELISA. At week 4, angiography and histomorphometric analysis were performed, mRNA levels of collagen I and III were assayed by RT-PCR and protein levels of TGF-beta1 and Smad2 in local vessel were assayed by Western blot., Results: Following 4 weeks treatment, ANG-(1-7) and ANG-(1-7) + A-779 group displayed a significant elevation in lumen diameter [(4.11 +/- 0.10) mm and (3.34 +/- 0.11) mm vs. (2.88 +/- 0.08) mm, P < 0.05, respectively] and reduction in neointimal thickness [(208 +/- 17) microm and (407 +/- 25) microm vs. (448 +/- 15) microm, P < 0.05, respectively], neointimal area [(0.27 +/- 0.09) mm2 and (0.38 +/- 0.01) mm2 vs. (0.41 +/- 0.02) mm2, P < 0.05, respectively] and restenosis rate [(28.1 +/- 2.7)% and (36.8 +/- 2.2)% vs. (40.1 +/- 2.7)%, P < 0.05, respectively] compared with control group. Collagen I, III mRNA and TGF-beta1, Smad2 protein levels were significantly elevated in control group, ANG-(1-7) group and ANG-(1-7) +A-779 group compared to sham group (P < 0.01 or P < 0.05) and reduced in ANG-(1-7) group compared to control group (all P < 0.05). Co-treatment with A-779 reversed the inhibitory action of ANG-(1-7). Plasma levels of ANG II postangioplasty were similar in control and ANG-(1-7) group and both were significantly higher than preoperation levels., Conclusion: ANG-(1-7) attenuates postangioplasty collagen synthesis in rabbits possibly through down-regulating the expression of TGF-beta1 and inhibiting the activation of Smad2 pathway.

Objective: To evaluate the side effects of non-steroidal anti-inflammatory drugs (NSAID) on gastric mucosa, and to study the preventive effects of teprenone in patients., Methods: 108 patients taking NSAID for more than 3 months with no infection of helicobacter pylori (Hp) were collected. All patients were screened by endoscopy and their upper gastrointestinal symptoms were evaluated. Then, 16 patients with ulcers were excluded and 92 patients were randomly divided into intervention group with teprenone and control group. After follow-up for 3 months, patients were screened again by endoscopy and their upper gastrointestinal symptoms were also evaluated. Specimens of gastric mucosa were studied by PAS dyeing, and Cyclooxygenase (COX) level were evaluated by immunohistochemical technique., Results: Of patients taking NSAIDs, the erosion was found in 48 (44.4%) patients while 16 (14.8%) were found with peptic ulcers. The damages were improved significantly (Z = -4.96, P = 0.000) in the intervention group with teprenone (n = 45) as compared with control group (n = 47) after follow-up for 3 months. Both the cox-1 level [31.1% (14/45) vs 6.7% (3/45), P = 0.003] and mucus thickness [66.7% (30/45) vs 13.3% (6/45), P= 0.000] also increased in the intervention group as compared with control group. No significant difference was found on COX-2 level between these two groups [28.9% (13/45) vs 31.1% (14/45), P = 0.82]., Conclusion: Long-term use of NSAID caused severe damages on gastric and duodenal mucosa; teprenone improved NSAID-related gastric side effects and increased the COX-1 level and mucus thickness.

Objective: To assess the effects of rhBNP on left ventricular (LV) remodeling in rats with acute myocardial infarction (AMI)., Methods: AMI was induced by ligating coronary artery in male Sprague Dawley rats. Two days after surgery, AMI rats received intravenous infusion of rhBNP (15 microg/kg or 5 microg/kg once daily, n = 15 each) or saline (placebo control, n = 15) through Jugular Vein. Sham-operated rats (n = 15) served as normal control. Four weeks later, hemodynamic measurements were performed, left ventricular weight (LVW), ratio of left ventricular weight to body weight (LVW/BW), left ventricular diameter (LVD) and infarct size were determined. Plasma angiotensin II and myocardial angiotensin II levels were also measured., Results: Compared with sham-operated rats, LVW, LVW/BW, LVD and myocardial angiotensin II level were significantly increased, while the LV systolic pressure (LVSP), +/- dp/dt were significantly reduced in saline treated AMI rats (all P < 0.05). LVW/BW, MI size, LVD and myocardial angiotensin II in rhBNP treated AMI rats were significantly lower [LVW: (492.6 +/- 34.0) mg, (498.8 +/- 47.8) mg, (570.0 +/- 24.2) mg, P < 0.01; LVW/BW: 2.0 +/- 0.2, 2.0 +/- 0.2, 2.3 +/- 0.1, P < 0.01; LVD: (25.3 +/- 2.9)%, (31.4 +/- 3.0)%, (46.4 +/- 3.0)%, P < 0.01; myocardial angiotensin II: (881.3 +/- 62.7) pg/L, (1186.0 +/- 94.5) pg/L, (2436.7 +/- 280.3) pg/L, P < 0.05], while LVSP and +/- dp/dt in rhBNP treatment groups were significantly increased than saline treated AMI rats (P < 0.05 or P < 0.01)., Conclusion: RhBNP is effective in attenuating left ventricular remodeling after AMI in rats.

Objective: To investigate the effect of chronic enhanced external counterpulastion (EECP) on gene expression profiles of arterial endothelial cells (ECs) of pigs fed with high-cholesterol diet., Methods: Eight male pigs were fed with high-cholesterol diet for 12 weeks to induce arteriosclerosis and subjected to EECP for accumulative 36 h (2 h every other day for 18 sessions). Another 8 pigs on cholesterol-enriched diet and 6 normally fed pigs served as the arteriosclerosis model group and normal control group, respectively, and the high-cholesterol diet was maintained until the end of EECP treatment. The coronary artery was then isolated for transmission electro microscopy, and the abdominal aorta was observed using Sudan III staining. The gene expression profiles in ECs from the thoracic aorta using cDNA microarrays., Results: Macrophages and foam cells were detected beneath the ECs in the coronary artery of pigs in the model group, but not in the other two groups. The ratios of Sudan III-positive area in the celiac aorta were significantly lower in normal control and EECP groups than in the model control group (P<0.05). Compared with the normal control group, the gene expressions of integrins-beta1 and CTGF were up-regulated in the model group. Compared with the model group, the expressions of integrins-beta1, CTGF and VCAM-1 were down-regulated and eNOS up-regulated in EECP group., Conclusion: Chronic EECP may reduce endothelial injury, down-regulate the gene expression level of integrin-beta1, CTGF and VCAM-1, lower cholesterol uptake and attenuate arterial endothelial inflammation to protect the pigs fed with high-cholesterol diet from arteriosclerosis.

Objective: To study the effect of hypertension and telmisartan treatment on the protein and gene expression of cardiac angiotensin-converting enzyme 2 (ACE2) in pressure-overloaded rats., Methods: Coarctation of suprarenal abdominal aorta was reproduced in 8 week-old male Sprague-Dawley (SD) rats and then randomized into 4 groups, including a sham group (n=15), a suprarenal aortic coarctation group (model group, n=12), a suprarenal aortic coarctation with low-dose Telmisartan treatment group (low-dose group, 2 mgxkg(-1)xd(-1), n=11) and a suprarenal aortic coarctation with high-dose Telmisartan treatment group(high-dose group, 10 mgxkg(-1)xd(-1), n=13). Telmisartan or equivalent amount of normal saline was gavaged 24 hours before the operation and once every day afterwards for 3 weeks. At the end of 3 weeks, the concentrations of angiotensin (AngII) in plasma and myocardium were measured by radioimmunoassay. Changes in both protein quantity and gene expressions of both ACE2 and ACE were determined by Western blotting analysis and reverse transcription-polymerase chain reaction (RT-PCR) technique, respectively., Results: Suprarenal abdominal aortic coarctation induced a significant increase in the plasma and myocardium AngII concentration [plasma: (495.1+/-55.6) ng/L vs. (269.2+/-39.5)ng/L, myocardium: (103.6+/-23.7) ng/g vs. (49.5+/-13.5) ng/g, both P<0.01] and expressions of gene and protein of ACE (P<0.01) and ACE2 (P<0.05). Telmisartan further increased the concentration of AngII in plasma and myocardium in a dose-dependent manner [plasma: (702.2+/-40.6) ng/L vs. (612.6+/-35.5) ng/L, myocardium (211.5+/-21.5) ng/g vs. (189.6+/-43.6) ng/g, both P<0.05], and induced a dose-dependent increase in both protein and gene expression of ACE2 (protein 1.16+/-0.06 vs. 0.79+/-0.04, gene 0.54+/-0.08 vs. 0.41+/-0.04, both P<0.05). Expression of ACE2 protein in low-dose and high-dose groups was increased by 1.0 and 1.58 folds respectively, and gene was increased by 1.3 and 1.6 folds (all P<0.05). The expression of ACE protein and gene in model group increased significantly (protein: 2.10+/-1.07 vs. 1.02+/-0.05, gene: 1.93+/-0.09 vs. 0.26+/-0.09, both P<0.01). Telmisartan had no significant effect on ACE gene and protein expressions (both P>0.05)., Conclusion: Suprarenal abdominal aortic coarctation induced a significant increases of ACE and ACE2 gene and protein expressions. Telmisartan induces a dose-dependent increases of cardiac ACE2 gene and protein expression,which may be the mechanism of its therapeutic effects.

Objective: To explore the effects of ischemic postconditioning on ischemia/reperfusion injury in isolated hypertrophied rat heart and investigate the signal transduction pathway changes induced by ischemia postconditioning., Methods: Cardiac hypertrophy was induced in rats by abdominal aortic banding, and isolated hypertrophied rat heart ischemia/reperfusion model was made by Langendorff technique to evaluate the effects of ischemia postconditioning on left ventricular systole pressure, coronary artery flow, creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) release, myocardial infarction size, and the level of myocardial phospho-protein kinase B/Akt (Ser473), phospho-glycogen synthase kinase-3beta (Ser9). Following groups were studied (n = 12 each group): IR, 30 min ischemia (I)/60 min Reperfusion (R); Post: 30 min ischemia, 6 circles of 10 s I/10 s R followed by 60 min R; Post Wort: 30 min ischemia, 6 circles of 10 s I/10 s R, wortmannin (10(-7) mol/L) followed by 60 min R; Wort: 30 min ischemia, wortmannin (10(-7) mol/L) followed by 60 min R., Results: Left ventricular systolic pressure and coronary artery flow were significantly increased, myocardial infarction size and the release of CPK, LDH significantly reduced in Post group compared to that in IR group. Phospho-protein kinase B/Akt (Ser473) and phospho-glycogen synthase kinase-3beta (Ser9) levels were also significantly higher in Post group than that in IR group. Phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin prevented the increase of phospho-protein kinase B/Akt (Ser473) and phospho-glycogen synthase kinase-3beta (Ser9) induced by ischemic postconditioning, but only partly abolished the cardioprotection of ischemic postconditioning., Conclusion: Ischemic postconditioning attenuates ischemia/reperfusion injury in isolated hypertrophied rat heart. The cardioprotective effects of ischemic postconditioning were partly mediated through PI3K/Akt/GSK-3beta signaling pathway.

Objective: To investigate the effect of telmisartan on the protein and gene expression of angiotensin-converting enzyme-2 (ACE2) in human umbilical vein endothelial cells (HUVECs)., Methods: HUVECs were treated with various concentrations of telmisartan (10(-7), 10(-6) and 10(-5) mol/L) for 24 hours. In a time-control experiment, HUVECs were treated with telmisartan at the final concentration of 10(-6) mol/L for 6, 12 and 24 hours, respectively. In another experiment, HUVECs were treated with PD123319 (10(-6) mol/L) only or combined with same final concentration of telmisartan for 12 hours, respectively. Changes in both protein and gene expression of ACE2 were determined with Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) technique, respectively., Results: Telmisartan induced a concentration and time dependent increase in both protein and gene expression of ACE2 (P<0.05 or P<0.01). Compared with control group, treatment of HUVECs with telmisartan at the concentration of 10(-7), 10(-6) and 10(-5) mol/L stimulated 1.5-, 2.7- and 4.6-fold increase in the ACE2 protein expression, as well as 1.2-, 2.3- and 4.5-fold increase in its gene expression, respectively. After treatment of HUVECs with telmisartan for 6, 12, and 24 hours at the concentration of 10(-6) mol/L, the ACE2 protein expression increased 1.6-, 2.7- and 4.2-fold, and its gene expression increased 1.3-, 2.3- and 4.0-fold, respectively. Compared with control and telmisartan groups, PD123319 had no effect on both protein and gene expression of ACE2 (P>0.05)., Conclusion: Telmisartan up-regulates the protein and gene expression of ACE2 in HUVECs in a concentration and time dependent manner. This effect may be mediated via its specific pathway.

Objective: To study the effects of enhanced external counterpulsation (EECP) on the vascular morphology, and endothelial function using experimentally induced hypercholesterolemic pigs., Methods: Thirty five male pigs were randomly divided into three groups: 7 normal control animals, 11 hypercholesterolemic animals, and 17 hypercholesterolemic animals receiving EECP. Serum cholesterol was measured. The coronary arteries and aortas were sampled for histopathologic and ultrastructural examination. The NF-kappaB protein expression of porcine coronary arteries was investigated by immunofluorescence., Results: Compared with the normal controls, serum cholesterol levels were significantly higher in the hypercholesterolemic animals with or without EECP. The plaque/intimal area ratio of the aorta decreased significantly in animals receiving EECP [(3.33 +/- 2.40)%, versus (12.03 +/- 7.12)% in those without EECP, P < 0.05]. Lipid deposition, endothelial damage and proliferation of smooth muscle cells were less severe in animals receiving EECP than those not. Moreover, activation and expression of NF-kappaB also decreased significantly (P < 0.05) in animals receiving EECP., Conclusions: EECP improves the morphology and function of vascular endothelium, and retards the development and progression of atherosclerosis, likely through the inhibition of NF-kappaB signaling pathway.

Objective: To study the effect of angiotensin-(1-7)[Ang-(1-7)]on fibrinolytic imbalance induced by oxidized low- density lipoprotein (ox-LDL) in cultured human umbilical vein endothelial cells (HUVECs)., Method: Cultured HUVECs were incubated for 24 h in the presence of Ang-(1-7), ox-LDL and A-779 at different concentrations either separately or in combination. The final concentrations of Ang-(1-7) were 10, 100 and 1,000 nmol/L, and those of ox-LDL were 25, 50 and 100 mg protein/L. The final concentration of A-779, an Ang-(1-7) receptor antagonist, was 100 nmol/L. Tissue plasminogen activator (t-PA) and its inhibitor-1(PAI-1) antigen in the medium were determined by enzyme-linked immunosorbent assay (ELISA) and their mRNA levels by reverse transcriptional (RT) PCR., Results: Ox-LDL (25-100 mg protein/L) dose-dependently increased PAI-1 release and up-regulated PAI-1 gene transcription, but decreased t-PA release and down-regulated t-PA gene transcription (P>0.001-0.05). Ang-(1-7) (100-1,000 nmol/L) dose-dependently decreased PAI-1 release and PAI-1 gene transcription (P>0.01-0.05) but had no effect on t-PA release and gene transcription. In the presence of ox-LDL, Ang-(1-7) lowered the increased levels of PAI-1 and PAI-1 mRNA, and elevated the levels of decreased t-PA and t-PA mRNA in the cells (P>0.01-0.05). The effects of Ang-(1-7) could be blocked by A-779., Conclusion: Angiotensin-(1-7) effectively modulates the fibrinolytic imbalance induced by ox-LDL via its specific receptor.

Objective: To investigate the influence of ACE inhibitor (perindopril) on the contractility and calcium transient and calcium handling proteins in ventricular myocytes from rats with experimental heart failure., Methods: Male Wistar rats were randomized to heart failure group treated with perindopril (CHF-T, 3 mg.kg(-1).d(-1)), heart failure group without treatment (CHF-C) and sham-operated group (PS) after heart failure was induced by constricting abdominal aorta for 16 weeks. All groups were further followed up for 12 weeks. Left ventricular myocytes were isolated, and single cell shortening fraction and [Ca(2+)](i) were simultaneously measured through laser scanning confocal microscope under the field stimulation (1.0 Hz). RT-PCR and Western blot were performed to evaluate the level of mRNA and protein of Na(+)-Ca(2+) exchanger (NCX(1)), sarcoplasmic Ca(2+)-ATPase (SERCA(2)) and phospholamban (PLB)., Results: The fraction of cell shortening (FS%) and [Ca(2+)](i max) (nmol/L) were significantly smaller in group CHF-C than group PS (FS%: 7.51 +/- 1.15 vs 13.21 +/- 1.49; [Ca(2+)](i max): 330.85 +/- 50.05 vs 498.16 +/- 14.07; both P < 0.01). And in CHF-T group, FS and [Ca(2+)](i max) were greater than those in CHF-C group. In CHF-C group, the left ventricular mRNA of NCX(1) and PLB were significantly higher than those in PS group (R(NCX)(1)/beta-Actin: 0.51 +/- 0.12 vs 0.19 +/- 0.06, P < 0.01; R(PLB)/beta-Actin: 0.26 +/- 0.12 vs 0.20 +/- 0.08, P = 0.045), yet SERCA(2) mRNA was lower than PS group (0.48 +/- 0.10 vs 0.80 +/- 0.11, P < 0.01). In CHF-T group, the mRNA levels of NCX(1) and SERCA(2) were just in the midst of the CHF-C and PS group, and had statistical significance respectively (all P < 0.05). In CHF - C and CHF - T group, the protein levels of NCX(1) were 1.141 +/- 0.047 and 1.074 +/- 0.081 times PS group, respectively (both P < 0.05), and SERCA(2) protein levels were respectively 0.803 +/- 0.100 and 0.893 +/- 0.084 times as high as in PS group (both P < 0.05). The protein expression of NCX(1) and SERCA(2) were also different between CHF-C and CHF-T groups (both P < 0.05)., Conclusion: ACE inhibitor could improve cardiac function in CHF through directly enhancing the contractility of single myocardial cell, and these effects were probably mediated by its role in preventing the deleterious changes of calcium transient and calcium handling proteins in CHF.

Objective: To investigate the effects of angiotensin-(1-7) on remodeling of myocardial collagen network in pressure-overloaded rats., Methods: A rat model of pressure-overloaded heart was induced by constriction of abdominal aorta. Seventy-five male Sprague Dawley rats were randomized to sham-operated group, model control group and angiotensin-(1-7) group. The rats of the latter two groups were treated with intravenous infusion of either angiotensin-(1-7) (25 microg x kg(-1) x h(-1)) or saline after operation. Ratio of left ventricular weight to body weight (LVW/BW) and myocardial collagen volume fraction (CVF) were determined at 1 and 4 weeks after operation. And types I and III collagen mRNA expressions were assessed with reverse transcription-polymerase chain reaction (RT-PCR)., Results: At 1 week after the operation, types I and III collagen mRNA expressions of the left ventricular myocardium in model group and angiotensin-(1-7) group were increased significantly compared with those in sham-operated group. But those in angiotensin-(1-7) group were significantly lower than that in model group. At 4 weeks after the operation, LVW/BW and CVF were increased significantly in model group and angiotension-(1-7) group compared with those in sham-operated group, but those in angiotension-(1-7) group were significantly lower than that of model group., Conclusion: Angiotensin -(1-7) can attenuate remodeling of myocardial collagen network in pressure-overloaded rats.