Endurance exercise training improves endothelium-dependent relaxation in brachial arteries from hypercholesterolemic male pigs

• Published in: Journal of applied physiology (1985) Vol. 99; no. 4; pp. 1412 - 1421
• Main Authors: Woodman, Christopher R, Thompson, Mark A, Turk, James R, Laughlin, M. Harold
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.10.2005; American Physiological Society
• Subjects: Acetylcholine - pharmacology; Animals; Biological and medical sciences; Blood vessels; Brachial Artery - drug effects; Brachial Artery - metabolism; Brachial Artery - physiopathology; Bradykinin - pharmacology; Caveolin 1 - metabolism; Endothelium, Vascular - physiopathology; Exercise; Fundamental and applied biological sciences. Psychology; Hogs; Hypercholesterolemia - physiopathology; Immunoblotting; Immunohistochemistry; In Vitro Techniques; Male; Nitric oxide; Nitric Oxide Synthase Type III - metabolism; Nitroprusside - pharmacology; Physical Conditioning, Animal; Physical Endurance; Superoxide Dismutase - metabolism; Superoxide Dismutase-1; Swine; Swine, Miniature; Vasodilation; Vasodilator Agents - pharmacology; Physical exercise; endothelium-derived hyperpolarizing factor: endothelial nitric oxide synthase; Physical training; Prostaglandin I2; Lipids; Smooth muscle; Male; Hyperlipoproteinemia; Lipoprotein; Relaxation; Endurance; Dyslipemia; Ungulata; vascular smooth muscle; Enzyme; prostacyclin; Brachial artery; Metabolic diseases; Cholesterol; Nitric-oxide synthase; Endothelium; Pig; Vertebrata; Mammalia; Hypercholesterolemia; Nitric oxide; Artiodactyla; Oxidoreductases
• DOI: 10.1152/japplphysiol.00293.2005
• ISSN: 8750-7587

Department of Biomedical Sciences, University of Missouri, Columbia, Missouri Submitted 16 March 2005 ; accepted in final form 17 June 2005 We tested the hypothesis that exercise (Ex) training attenuates hypercholesterolemia-induced impairment of endothelium-dependent relaxation (EDR) in brachial (Br) arteries of adult male pigs by enhancing nitric oxide (NO)-mediated EDR. Adult male pigs were fed a normal-fat (NF) or high-fat/cholesterol (HF) diet for 20 wk. Four weeks after the diet was initiated, pigs were trained or remained sedentary (Sed) for 16 wk, yielding four groups: 1 ) NF-Sed, 2 ) NF-Ex, 3 ) HF-Sed, and 4 ) HF-Ex. EDR of Br artery rings was assessed in vitro with acetylcholine (ACh) and bradykinin (BK). ACh- and BK-induced relaxation was not impaired by HF; however, relaxation responses were enhanced by Ex in NF and HF arteries. To determine the mechanism(s) by which Ex improved EDR, ACh- and BK-induced relaxation was assessed in the presence of N G -nitro- L -arginine methyl ester ( L -NAME; to inhibit NO synthase), indomethacin (Indo; to inhibit cyclooxygenase), or L -NAME + Indo. ACh- and BK-induced relaxation was inhibited by L -NAME, and L -NAME + Indo, in all groups of arteries. Indo did not inhibit ACh-induced relaxation in any group but did inhibit BK-induced relaxation in HF-Ex arteries. In the presence of L -NAME or L -NAME + Indo, ACh- and BK-induced relaxation in HF-Ex arteries remained greater than in HF-Sed arteries. However, in the presence of Indo, ACh-induced relaxation in HF-Ex arteries was no longer greater than in HF-Sed arteries. These results indicate that EDR is not impaired by hypercholesterolemia in Br arteries from adult male pigs; however, Ex improves EDR in HF Br arteries by enhancing production of endothelium-derived hyperpolarizing factor and/or prostacyclin. nitric oxide; prostacyclin; endothelium-derived hyperpolarizing factor; endothelial nitric oxide synthase; vascular smooth muscle Address for reprint requests and other correspondence: C. R. Woodman, Dept. of Biomedical Sciences, W108 Veterinary Medicine, 1600 E. Rollins Rd., Univ. of Missouri, Columbia, MO 65211 (e-mail: woodmanc{at}missouri.edu )