title: Improvement of Acetylcholine-Induced Vasodilation by Acute Exercise in Ovariectomized Hypertensive Rats.
abstract: 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. Age-matched WKY rats were used as the normotensive control group. The SHR-OE group ran on a motor-driven 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 (ACh-induced) 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 SNP-induced 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.
authors.affiliation: Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China.|Orthopaedic Research Center, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China.
authors.forename: Tsung-Lin
authors.initials: TL
authors.lastname: Cheng
authors.affiliation: Graduate Institute of Clinical Medical Science, China Medical University, Taichung 40402, Taiwan, Republic of China.
authors.forename: Yi-Yuan
authors.initials: YY
authors.lastname: Lin
authors.affiliation: Department of Occupational Therapy, College of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan, Republic of China.
authors.forename: Chia-Ting
authors.initials: CT
authors.lastname: Su
authors.affiliation: Department of Sports Sciences, University of Taipei, Taipei 11153, Taiwan, Republic of China.
authors.forename: Chun-Che
authors.initials: CC
authors.lastname: Hu
authors.affiliation: Department of Sports Sciences, University of Taipei, Taipei 11153, Taiwan, Republic of China.
authors.forename: Ai-Lun
authors.initials: AL
authors.lastname: Yang
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010052:Ovariectomy; D018384:Oxidative Stress / Q000187:drug effects; D010805:Physical Conditioning, Animal; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D057185:Sedentary Behavior; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D019001:Nitric Oxide Synthase; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester