Improvement of Acetylcholine-Induced Vasodilation by Acute Exercise in Ovariectomized Hypertensive Rats

Tsung-Lin Cheng ； Yi-Yuan Lin ； Chia-Ting Su ； Chun-Che Hu ； Ai-Lun Yang

《The Chinese Journal of Physiology》 59卷3期 (2016/06) Pp. 165-172

https://doi.org/10.4077/CJP.2016.BAE387

並列摘要

Postmenopause is associated with the development of cardiovascular disease, such as hypertension. However, limited information is available regarding effects of exercise on cardiovascular responses and its underlying mechanisms in the simultaneous postmenopausal and hypertensive status. We aimed to investigate whether acute exercise could enhance vasodilation mediated by acetylcholine (ACh) and sodium nitroprusside (SNP) in ovariectomized hypertensive rats. The fifteen-week-old female spontaneously hypertensive rats (SHR) were bilaterally ovariectomized, at the age of twenty-four weeks, and randomly divided into sedentary (SHR-O) and acute exercise (SHR-OE) groups. Agematched WKY rats were used as the normotensive control group. The SHR-OE group ran on a motordriven treadmill at a speed of 24 m/min for one hour in a moderate-intensity program. Following a single bout of exercise, rat aortas were isolated for the evaluation of the endothelium-dependent (AChinduced) and endothelium-independent (SNP-induced) vasodilation by the organ bath system. Also, the serum levels of oxidative stress and antioxidant activities, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase, were measured after acute exercise among the three groups. We found that acute exercise significantly enhanced the ACh-induced vasodilation, but not the SNPinduced vasodilation, in ovariectomized hypertensive rats. This increased vasodilation was eliminated after the inhibition of nitric oxide synthase (NOS). Also, the activities of SOD and catalase were significantly increased after acute exercise, whereas the level of MDA was comparable among the three groups. These results indicated that acute exercise improved the endothelium-dependent vasodilating response to ACh through the NOS-related pathway in ovariectomized hypertensive rats, which might be associated with increased serum antioxidant activities.

並列關鍵字

antioxidant activity ； exercise ； hypertension ； ovariectomy ； vasodilation

參考文獻

Barton, M.,Meyer, M.R.(2009).Postmenopausal hypertension: mechanisms and therapy.Hypertension.54,11-18.

Briones, A.M.,Touyz, R.M.(2010).Oxidative stress and hypertension: current concepts.Curr. Hypertens. Rep..12,135-142.

Ceriello, A.(2008).Possible role of oxidative stress in the pathogenesis of hypertension.Diabetes Care.31,S181-S184.

Chandrashekhar, Y.,Anand, I.S.(1991).Exercise as a coronary protective factor.Am. Heart J..122,1723-1739.

Chen, H.I.,Chiang, I.P.,Jen, C.J.(1996).Exercise training increases acetylcholine-stimulated endothelium-derived nitric oxide release in spontaneously hypertensive rats.J. Biomed. Sci..3,454-460.