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Microvascular angioadaptation after endurance training with l ‐arginine supplementation in rat heart and hindleg muscles
Author(s) -
Suzuki Junichi
Publication year - 2005
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2005.031138
Subject(s) - arginine , endocrinology , medicine , ventricle , vascular endothelial growth factor , angiogenesis , endurance training , nitric oxide , western blot , nitric oxide synthase , chemistry , vegf receptors , biochemistry , amino acid , gene
This study was designed to examine whether dietary l ‐arginine supplementation modulates exercise‐induced angiogenesis and vascular endothelial growth factor (VEGF) expression in female Wistar rats. Exercise training (running) lasted for 6 weeks at 25 m min −1 on a 20% gradient for 10–60 min day −1 . Rats in the l ‐arginine‐treated groups drank water containing 4% l ‐arginine. Histochemical identification of capillary profiles showed that training with l ‐arginine significantly increased the capillary/fibre (C/F) ratio in the subendocardium of the left ventricle, whereas training alone did not. Because of a significantly higher fibre cross‐sectional area, a concomitant, but not significant, decrease in capillary density was also observed. In the hindleg muscles, training with l ‐arginine significantly increased the C:F ratio, although the degree of change was the same as that observed after training alone. Western blot analysis showed that training with l ‐arginine significantly increased VEGF protein expression by 1.7‐fold in the left ventricle, while the increase with training alone was insignificant. In the soleus muscle, although VEGF protein expression was elevated insignificantly after training (2.8‐fold), training with l ‐arginine significantly increased the protein levels (3.8‐fold). Tissue endothelial nitric oxide synthase protein levels did not changed after either training or l ‐arginine treatment. The present results suggest that l ‐arginine supplementation causes additional effects on exercise‐induced angiogenesis in the rat heart by promoting VEGF expression.