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Objective(s): Due to the presence of the cholinergic system in the lateral periaqueductal gray (lPAG) column, the cardiovascular effects of acetylcholine (ACH) and its receptors in normotensive and hydralazine (HYD) hypotensive rats in this area were evaluated. Materials and Methods: After anesthesia, the femoral artery was cannulated and systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), and also electrocardiogram for evaluation of low frequency (LF) and high frequency (HF) bands, important components of heart rate variability (HRV), were recorded. ACH, atropine (Atr, a muscarinic antagonist), and hexamethonium (Hex, an antagonist nicotinic) alone and together microinjected into lPAG, changes (Δ) of cardiovascular responses and normalized (n) LF, HF, and LF/HF ratio were analyzed. Results: In normotensive rats, ACH decreased SBP and MAP, and enhanced HR while Atr and Hex did had no effects. In co-injection of Atr and Hex with ACH, only ACH+Atr significantly attenuated parameters. In HYD hypotension, ACH had no affect but Atr and Hex significantly improved the hypotensive effect. Co-injection of Atr and Hex with ACH decreased the hypotensive effect but the effect of Atr+ACH was higher. In normotensive rats, ACH decreased nLF, nHF, and nLF/nHF ratio. These parameters in the Atr +ACH group were significantly higher than in ACH group. In HYD hypotension nLF and nLF/nHF ratio increased which was attenuated by ACH. Also, Atr+ACH decreased nLF and nLF/nHF ratio and increased nHF. Conclusion: The cholinergic system of lPAG mainly via muscarinic receptors has an inhibitory effect on the cardiovascular system. Based on HRV assessment, peripheral cardiovascular effects are mostly mediated by the parasympathetic system. [ABSTRACT FROM AUTHOR]

Objective(s): In the present study, the cardiovascular effects of glutamate NMDA receptor of the pedunculopontine tegmental nucleus (PPT) in normotensive and hydralazine (HLZ) hypotensive rats were evaluated. Materials and Methods: In the normotensive condition, MK-801(1 nmol; an NMDA receptor antagonist) and L-glutamate (L-Glu, 50 nmol an agonist) alone and together were microinjected into the nucleus using a stereotaxic device. In hypotensive condition, 2 min after induction of hypotension by HLZ (10 mg/kg, intravenous), drugs, same as in normotensive condition, were microinjected into the PPT. Recorded mean arterial pressure (MAP), systolic blood pressure (SBP), and heart rate (HR) were recorded throughout the experiment by a Power lab apparatus that was connected to a catheter inserted into the femoral arty. The cardiovascular changes (Î") induced by microinjection drugs were computed and statistically analyzed. Results: In the normotensive condition, L-Glu significantly increased ΔMAP and ΔSBP (P<0.001) and decreased ΔHR (P<0.01) compared with the control. MK-801 alone significantly increased HR (P<0.05) while co-injected with L-Glu + MK-801 it significantly attenuated the L-Glu effect on ΔMAP and ΔSBP but augmented ΔHR (P<0.01). In the hydralazine hypotension condition, L-Glu significantly improved hypotension (P<0.01) and deteriorated bradycardia induced by HLZ (P<0.05). MK-801 alone did not significantly affect ΔMAP, ΔSBP, and ΔHR but when co-injected with L-Glu (L-Glu + MK-801) it could significantly attenuate the cardiovascular effect of L-Glu in the PPT. Conclusion: We found that activation of NMDA receptors of the glutamatergic system in the PPT evoked blood pressure and inhibited HR in both normotensive and hypotensive conditions in rats. [ABSTRACT FROM AUTHOR]

Objective(s): Periaqueductal gray (PAG) is a mesencephalic area divided into four columns including ventrolateral periaqueductal gray (vlPAG). vlPAG plays a role in cardiovascular regulation during normal and hemorrhagic (Hem) conditions. Due to presence of glutamate in this area, we evaluated the effect of glutamatergic receptors of this area on cardiovascular activity in normotensive and hypovolemic Hem rats. Materials and Methods: Animals were divided into twelve groups: saline (vehicle), Glutamate, GYK52466 (non-NMDA receptor antagonist), and MK801 (NMDA receptor antagonist) with and without Glu microinjected into vlPAG in normal and Hem conditions. Following the femoral artery cannulating and microinjecting, changes (Δ) of heart rate (HR), systolic blood pressure (SBP), and mean arterial pressure (MAP) were recorded via a PowerLab unit. Results: In normotensive conditions, microinjection of Glu increased ΔMAP, ΔSBP, and ΔHR (P<0.001). MK-801 and GYKI-52466 nonsignificant reduced cardiovascular responses than vehicle while their changes were significant compared with glutamate (P<0.001). Co-injection of GYKI- 52466 with Glu did not significantly reduce ΔSBP and ΔMAP induced by Glu (P>0.05) but co-injection of MK-801 with Glu significantly attenuate these effects(P<0.01). In Hem, Glu increased ΔSBP, ΔMAP, and ΔHR (P<0.05). GYKI-52466 alone did not change cardiovascular responses but MK-801 decreased ΔSBP than Hem (P<0.01). Co-injection of GYKI-52466 with Glu had significant(P<0.05) but MK-801 with Glu had no significant effect compared with Hem (P>0.05). Conclusion: The glutamatergic system of vlPAG increases cardiovascular values that are mostly mediated through the NMDA receptor. Since vlPAG is well known as an inhibitory region, it seems that glutamate does not have a noteworthy cardiovascular role in vlPAG during Hem and normal conditions. [ABSTRACT FROM AUTHOR]

Objective(s): The 5-hydroxytryptamine1A (5-HT1A) receptor is one of the serotonin receptors in the brain, which regulates cardiovascular responses, especially in hemorrhage. Presence of this receptor in the cuneiform nucleus (CnF) has been shown. The present study evaluates the cardiovascular effect of this receptor of the CnF in normal and hypotensive hemorrhagic rats. Materials and Methods: Agonist (8-OH-DPAT) and antagonist (WAY-100635) of 5-HT1A microinjected into the CnF in basal and hemorrhagic conditions and cardiovascular responses were evaluated. Hemorrhage induced by blood withdrawal from the femoral artery and 2 min after that drugs microinjected. Time course and peak changes (A) of the mean arterial pressure (MAP), systolic blood pressure (SBP) and heart rate (AHR) were obtained and compared to the control and hemorrhage groups. Results: In basal condition, 8-OH-DPAT significantly decreased ASBP, AMAP and AHR compared to the control (P<0.05-P<0.01), while way-100635 did not have a significant effect. Hypotension and tachycardia induced by hemorrhage ameliorated by agonist (P<0.05-P<0.01), while antagonist deteriorated hypotension (P<0.05) but attenuated tachycardia (P<0.01). Conclusion: This study shows that 5-HT1A receptor of the CnF involves in regulation of the cardiovascular responses. However, this effect in basal and hemorrhage conditions is different. [ABSTRACT FROM AUTHOR]

Objective(s): The aim of current study was to evaluate improving effects of pioglitazone as an agonist of peroxisome proliferator-activated receptor gamma (PPARγ), on brain-derived neurotrophic factor (BDNF) and cytokines as well as tissue oxidative damage criteria in the hippocampus in a rat model of lipopolysaccharide (LPS) induced memory impairment. Materials and Methods: The rats were classified and treated as follows (10 rats per group): (1) vehicle, (2) vehicle before LPS (1 mg/kg, 120 min before memory tests), (3-5) pioglitazone 10, 20 or 30 mg/kg 30 min before LPS. Finally, the hippocampal tissues were collected for biomedical analyses. Results: In the Morris water maze test, the LPS group, had a longer latency to find the platform while they spent a shorter time in the target quadrant in the probe trial. In the passive avoidance test, the animals of the LPS group had shorter delay times to enter the dark compartment than those of the control group. Treatment with 20 and 30 mg of pioglitazone corrected these parameters. In the hippocampus of LPS group interleukin-6, tumor necrosis factor-α, nitric oxide metabolites, and malondialdehyde were higher while thiol, BDNF, and IL-10 concentrations and the activities of catalase (CAT) and superoxide dismutase (SOD) were lower than the control group. Treatment by both doses of 20 and 30 mg of pioglitazone corrected the biochemical parameters in the hippocampus. Conclusion: The current findings revealed that pioglitazone protected the rats from learning and memory impairment induced by LPS. The effects were associated with improvement of cytokines, oxidative stress criteria, and BDNF. [ABSTRACT FROM AUTHOR]

Objective(s): Cholinergic neurons are important neurons in the Pedunculopontine tegmental nucleus (PPT). In this study, nicotinic receptor of the PPT in central cardiovascular regulation in the anesthetized rat was evaluated. Materials and Methods: Saline, acetylcholine (Ach; doses: 90 and 150 nmol), hexamethonium (Hexa; doses: 100 and 300 nmol) and higher doses of Hexa (300 nmol) + Ach (150 nmol) microinjected into the PPT. The femoral artery was cannulated and cardiovascular responses were continuously recorded by a power lab system. After injection of drugs, peak changes of mean arterial pressure (AMAP), systolic blood pressure (ASBP) and heart rate (AHR) calculated and compared with saline group. Results: The ASBP and AMAP significantly decreased by two doses of Ach (P<0.05 to P<0.001) but AHR did not change. Two doses 100 (P<0.05) and 300 nmol (P<0.01) of Hexa significantly increased AHR but did not alter the AMAP or ASBP. Co-injection of Hexa + Ach significantly strengthened the AHR induced by Hexa alone (P<0.01) but did not affect AMAP or ASBP. Conclusion: These results indicate that nicotinic receptor of the PPT has an inhibitory effect on AHR with no significant effect on AMAP or ASBP. [ABSTRACT FROM AUTHOR]

Objective(s): Nitric oxide (NO) is an important neurotransmitter in central nervous system involved in central cardiovascular regulation. The presence of NO in the pedunculopontine tegmental (PPT) nucleus has been shown, but its cardiovascular effect has not been determined. In the present study, the cardiovascular effect of NO in the PPT nucleus was evaluated. Materials and Methods: After induction of anesthesia, a polyethylene catheter (PE-50) filled with heparinized saline inserted into the femoral artery, and the blood pressure (BP) and heart rate (HR) were continuously recorded. Animals were then placed in a stereotaxic apparatus and maximum changes of mean arterial pressure (ΔMAP) and heart rate (ΔHR) after microinjection of two doses of NG-nitro-L-arginine methyl ester (L-NAME, 30 and 90 nmol), L-arginine (L-Arg 10 and 50 nmol) and sodium nitroprusside (SNP, 9 and 27 nmol) into the PPT were provided and compared with control group (One-way ANOVA). Results: Both doses of L-NAME significantly increased ΔMAP compared to control (P<0.05 and P<0.01, respectively). ΔHR only in higher dose (90 nmol) significantly increased compared to control (P<0.05). Two doses of L-Arg (10 and 50 nmol/150 nl) had no significant effect on ΔMAP or ΔHR. Higher dose of SNP (27 nmol) significantly decreased ΔMAP (P<0.05) and its both doses significantly decreased ΔHR compared to control (P<0.05 and P<0.001, respectively). Effect of higher dose on ΔHR was significantly higher than the lower dose (P<0.05). Conclusion: Our results show an inhibitory effect of the nitrergic system of the PPT on central cardiovascular system. [ABSTRACT FROM AUTHOR]

Rosa damascena mill L., known as Gole Mohammadi in Iran is one of the most important species of Rosaceae family flowers. R. damascena is an ornamental plant and beside perfuming effect, several pharmacological properties including anti-HIV, antibacterial, antioxidant, antitussive, hypnotic, antidiabetic, and relaxant effect on tracheal chains have been reported for this plant. This article is a comprehensive review on pharmacological effects of R. damascena. Online literature searches were performed using Medline, Pubmed, Iran medex, Scopus, and Google Scholar websites backed to 1972 to identify researches about R. damascena. Searches also were done by going through the author's files and the bibliographies of all located papers. [ABSTRACT FROM AUTHOR]

Objectives: The 5-hydroxytryptamine1A (5-HT 1A ) receptor is one of the serotonin receptors in the brain, which regulates cardiovascular responses, especially in hemorrhage. Presence of this receptor in the cuneiform nucleus (CnF) has been shown. The present study evaluates the cardiovascular effect of this receptor of the CnF in normal and hypotensive hemorrhagic rats., Materials and Methods: Agonist (8-OH-DPAT) and antagonist (WAY-100635) of 5-HT 1A microinjected into the CnF in basal and hemorrhagic conditions and cardiovascular responses were evaluated. Hemorrhage induced by blood withdrawal from the femoral artery and 2 min after that drugs microinjected. Time course and peak changes (∆) of the mean arterial pressure (MAP), systolic blood pressure (SBP) and heart rate (∆HR) were obtained and compared to the control and hemorrhage groups., Results: In basal condition, 8-OH-DPAT significantly decreased ∆SBP, ∆MAP and ∆HR compared to the control ( P< 0.05- P< 0.01), while way-100635 did not have a significant effect. Hypotension and tachycardia induced by hemorrhage ameliorated by agonist ( P< 0.05- P< 0.01), while antagonist deteriorated hypotension ( P< 0.05) but attenuated tachycardia ( P< 0.01)., Conclusion: This study shows that 5-HT 1A receptor of the CnF involves in regulation of the cardiovascular responses. However, this effect in basal and hemorrhage conditions is different.

Objectives: The aim of current study was to evaluate improving effects of pioglitazone as an agonist of peroxisome proliferator-activated receptor gamma (PPARγ), on brain-derived neurotrophic factor (BDNF) and cytokines as well as tissue oxidative damage criteria in the hippocampus in a rat model of lipopolysaccharide (LPS) induced memory impairment., Materials and Methods: The rats were classified and treated as follows (10 rats per group): (1) vehicle, (2) vehicle before LPS (1 mg/kg, 120 min before memory tests), (3-5) pioglitazone 10, 20 or 30 mg/kg 30 min before LPS. Finally, the hippocampal tissues were collected for biomedical analyses., Results: In the Morris water maze test, the LPS group, had a longer latency to find the platform while they spent a shorter time in the target quadrant in the probe trial. In the passive avoidance test, the animals of the LPS group had shorter delay times to enter the dark compartment than those of the control group. Treatment with 20 and 30 mg of pioglitazone corrected these parameters. In the hippocampus of LPS group interleukin-6, tumor necrosis factor-α, nitric oxide metabolites, and malondialdehyde were higher while thiol, BDNF, and IL-10 concentrations and the activities of catalase (CAT) and superoxide dismutase (SOD) were lower than the control group. Treatment by both doses of 20 and 30 mg of pioglitazone corrected the biochemical parameters in the hippocampus., Conclusion: The current findings revealed that pioglitazone protected the rats from learning and memory impairment induced by LPS. The effects were associated with improvement of cytokines, oxidative stress criteria, and BDNF., Competing Interests: Authors declare no conflicts of interest.