The present study was undertaken to measure the effects of thiopental and thiamylal on isolated thoracic aortic hlical strips in normotensive Wistar rats(NWR) and spontaneously hypertensive rats(SHR). Phenylphrine(10(-9) ~ 10(-5) M) caused a dose-dependant contraction in thoracic aortic strips contracted with 30mM KCI in NWR and SHR. The contraction induced by 30mM KCI was taken as 100% and the mean absolute values of NWR and SHR were 463+/-30 and 457+/-38mg, respectively. The ED50 of phenylphrine in thoracic aortic strips contracted with 30mM KCI in NWR and SHR was (2.3+/-1.2) X 10(-8) M and (2.1+/-1.1) X 10(-9) M, respectively. There were no significant differences in the contractile response of thoracic aorta from NWR and SHR to 30mM KCI. In helically cut strips of thoracic aorts contracted with 30mM KCI, the cumulative administration of thiopental (10(-5) ~ 10(-3) M) caused a dose related contraction in NWR and SHR. The contraction induced by 30mM KCI was taken as 100% and the mean absolute values of NWR and SHR were 496+/-31 and 541+/-69mg, respectively. There were significant differences (p<0.05 and p<0.01) in the contractile responses of thoracic aorta from NWR and SHR to thiamylal(3X10(-4) and 10(-3) M). The dose-related contraction to thiamylal was greater than that to thiopental in NWR and SHR.
Aorta, Thoracic* ; Rats, Inbred SHR* ; Thiamylal* ; Thiopental*

No abstract available.
Adenosine* ; Plasma* ; Rats, Inbred SHR* ; Renin*

No abstract available.
Coronary Circulation* ; Heart* ; Rats, Inbred SHR*

No abstract available.
Brain* ; Glutamic Acid* ; Intracranial Aneurysm ; Ischemia* ; Prosencephalon* ; Rats, Inbred SHR*

Activation of peripheral respiratory chemoreceptors provokes respiratory and cardiovascular reflexes, providing a novel understanding of pathogenic mechanism of hypertension. Here we hypothesize that activation of peripheral respiratory chemoreceptors by hypoxia causes enhanced cardiorespiratory activity in conscious spontaneously hypertensive rats (SHRs). Using whole body plethysmography in combination with radio telemetry, pulmonary ventilation, arterial blood pressure and heart rate were examined in SHRs and Wistar-Kyoto (WKY) rats. We found that exposure to hypoxia induced greater increases in tidal volume and minute ventilation volume in SHRs compared to WKY rats. In addition, hypoxia caused a robust increase in arterial blood pressure and heart rate in SHRs relative to WKY counterparts. After carotid body denervation, the hypoxic ventilatory response was significantly decreased in both SHRs and WKY rats, but without significant difference between the two strains; moreover, the differences of arterial blood pressure and heart rate changes during hypoxic exposure were statistically insignificant between SHRs and WKY rats. It is concluded that hypoxia remarkably potentiates cardiorespiratory activity in the SHRs, suggesting an enhanced sensitivity of carotid bodies to hypoxia.
Animals ; Blood Pressure ; Heart Rate ; Hypertension ; physiopathology ; Hypoxia ; physiopathology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY

Objective: To study the effects of aerobic exercise training on renal fibrosis in spontaneously hypertensive rats (SHR), and to explore the protective effect of exercise on renal damage in hypertensive rats. Methods: Eight-week-old male SHR and Wistar Kyoto rats of the same age (WKY) were randomly divided into 4 groups (n=6): sedentary WKY control group (WKY-S), sedentary SHR control group (SHR-S), low-intensity exercise group (SHR-L) and medium-intensity exercise group (SHR-M). SHR-L group and SHR-M group were set at a slope of 0° at 14 m/min (35% of the maximum aerobic speed) and 20 m/min (50% of the maximum aerobic speed), running on a sports treadmill for 14 weeks, 5 times a week, and 60 min each time. WKY-S and SHR-S groups were kept quietly. Blood pressure was measured 72 hours after exercise training. And the serum levels of creatinine (Scr) and BUN were detected. The morphology of renal tissue was observed by hematoxylin and eosin (HE) staining. The collagen deposition of renal tissue was observed by Masson staining, and the renal collagen volume fraction (CVF) was calculated. Results: Compared with WKY-S group, blood pressure, serum Scr and BUN, kidney CVF levels and AngⅡ, AT1R, TGF-β, α-SMA, CTGF expressions in SHR-S group were increased significantly (P＜0.05). Compared with SHR-S group, blood pressure, serum Scr and BUN, kidney CVF level and AngⅡ, AT1R, TGF-β, α-SMA, CTGF expressions in SHR-L and SHR-M groups were decreased significantly (P＜0.05) and the decreasing trend was more obvious in SHR-M group (P＜0.05). Conclusion: Aerobic exercise can improve renal fibrosis and renal function in spontaneously hypertensive rats by inhibiting the AngⅡ-AT1R-TGF-β pathway.
Animals ; Fibrosis ; Kidney Diseases ; Male ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Transforming Growth Factor beta

The hyperactivity of cholinergic system in the RVLM of spontaneously hypertensive rats (SHR) may contribute to the sustained elevation of blood pressure. However, the hyperactivity mechanisms of cholinergic system are controversial. Thus, to clarify the mechanisms of cholinergic hyperactivity in RVLM of the SHR, we studied the activities of enzymes that participate in the biosynthesis and degradation of acetylcholine (ACh) and the density of muscarinic receptors in RVLM of the 14- to 18-week-old SHR and age-marched Wistar Kyoto rats (WKY). Choline acetyltransferase activity was far greater in RVLM of SHR than that of WKY. (3H)ACh release from RVLM was also greater in SHR than in WKY. Acetylcholinesterase activity and (3H)NMS binding of RVLM slice of SHR were not significantly different from that of WKY. These results suggest that the enhanced cholinergic mechanisms in the RVLM of SHR is due to the enhanced presynaptic cholinergic tone rather than the altered postsynaptic mechanisms.
Acetylcholine ; Acetylcholinesterase ; Blood Pressure ; Choline O-Acetyltransferase ; Rats, Inbred SHR* ; Rats, Inbred WKY ; Receptors, Muscarinic

OBJECTIVETo explore the effect of temperature dropping process in cold air on the coagulation function both in healthy and hypertensive rats.

METHODSTwenty-four male healthy Wistar rats and 24 male spontaneous hypertensive rats (SHR) were randomly divided into the minimum temperature group (Tim), Tmin control group (Tmin-c), recovery temperature group (Tr) and Tr control group (Tr-c), With the simulated temperature dropping process of a cold air, collected from Zhangye city in March of 2011, the groups of Tmin and Tr were exposed to this process. Both at the Tmin and Tr, blood were collected from the rats for coagulation function measurements.

RESULTSCompared with the control group, no significant difference was found in the results of activated partial thrombin time(APIT), pro-thrombin time (PF) and thrombin time (TT) between any groups in any strains (P > 0.05). The fibrinogen (Fbg) and fibrinogen-time were found to be obvious higher and shorter in Tmin and Tr of healthy rats and in Tmin of hypertensive rats in contrast to the control group. Hypertensive rats had higher level of fibrinogen and shorter level of fibrinogen-time.

CONCLUSIONThe temperature dropping process induced the increase of plasma Fbg both in the healthy and hypertensive subjects, which might be the reason to explain the higher occurrence of cardiovascular diseases event especially these activated through the formation of thrombin during cold air stress. Besides, the coagulation function of healthy subjects was more likely to be affected by cold air than the hypertensive subjects.

Animals ; Blood Coagulation ; Cold Temperature ; Hypertension ; physiopathology ; Male ; Rats ; Rats, Inbred SHR ; Rats, Wistar ; Thrombin Time

Animals ; Blood Vessels ; pathology ; ultrastructure ; Cochlea ; blood supply ; Female ; Male ; Rats ; Rats, Inbred SHR ; Rats, Wistar

Diabetes is associated with an increased risk of cardiovascular complications. Dipeptidyl peptidase-4 (DPP-IV) inhibitors are used clinically to reduce high blood glucose levels as an antidiabetic agent. However, the effect of the DPP-IV inhibitor gemigliptin on ischemia/reperfusion (I/R)-induced myocardial injury and hypertension is unknown. In this study, we assessed the effects and mechanisms of gemigliptin in rat models of myocardial I/R injury and spontaneous hypertension. Gemigliptin (20 and 100 mg/kg/d) or vehicle was administered intragastrically to Sprague-Dawley rats for 4 weeks before induction of I/R injury. Gemigliptin exerted a preventive effect on I/R injury by improving hemodynamic function and reducing infarct size compared to the vehicle control group. Moreover, administration of gemigliptin (0.03% and 0.15%) powder in food for 4 weeks reversed hypertrophy and improved diastolic function in spontaneously hypertensive rats. We report here a novel effect of the gemigliptin on I/R injury and hypertension.
Animals ; Blood Glucose ; Hemodynamics ; Hypertension ; Hypertrophy ; Models, Animal ; Rats ; Rats, Inbred SHR ; Rats, Sprague-Dawley