SOD-1 expression in pig coronary arterioles is increased by exercise training.
Coronary arterioles of exercise-trained (EX) pigs have enhanced nitric oxide (NO.)-dependent dilation. Evidence suggests that the biological half-life of NO. depends in part on the management of the superoxide anion. The purpose of this study was to test the hypothesis that expression of cytosolic copper/zinc-dependent superoxide dismutase (SOD)-1 is increased in coronary arterioles as a result of exercise training. Male Yucatan pigs either remained sedentary (SED, n = 4) or were EX (n = 4) on a motorized treadmill for 16-20 wk. Individual coronary arterioles ( approximately 100-microm unpressurized internal diameter) were dissected and frozen. Coronary arteriole SOD-1 protein (via immunoblots) increased as a result of exercise training (2.16 +/- 0.35 times SED levels) as did SOD-1 enzyme activity (measured via inhibition of pyrogallol autooxidation; approximately 75% increase vs. SED). In addition, SOD-1 mRNA levels (measured via RT-PCR) were higher in EX arterioles (1.68 +/- 0.16 times the SED levels). There were no effects of exercise training on the levels of SOD-2 (mitochondrial), catalase, or p67(phox) proteins. Thus chronic aerobic exercise training selectively increases the levels of SOD-1 mRNA, protein, and enzymatic activity in porcine coronary arterioles. Increased SOD-1 could contribute to the enhanced NO.-dependent dilation previously observed in EX porcine coronary arterioles by improving management of superoxide in the vascular cell environment, thus prolonging the biological half-life of NO.
Rush
J W
JW
Department of Veterinary Biomedical Sciences and Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri 65211, USA. jwerush@uwaterloo.ca
Laughlin
M H
MH
Woodman
C R
CR
Price
E M
EM
D000818:Animals; D001160:Arterioles / Q000201:enzymology; D001835:Body Weight / Q000502:physiology; D002374:Catalase / Q000378:metabolism; D003331:Coronary Vessels / Q000201:enzymology*; D015151:Immunoblotting; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000502:physiology; D010750:Phosphoproteins / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000502:physiology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013556:Swine, Miniature / Q000378:metabolism*
D007527:Isoenzymes; D010750:Phosphoproteins; D012333:RNA, Messenger; C079789:neutrophil cytosol factor 67K; D002374:Catalase; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1