Endothelium-derived nitric oxide activity in forearm vessels of tennis players.
The aim of this study was to determine whether physical conditioning induced by a repetitive exercise stimulus would elicit changes in the response of forearm resistance vessels to an infusion of substances that modulate nitric oxide synthesis. Forearm blood flow responses to a 5-min ischemic stimulus and intrabrachial infusion of acetylcholine, sodium nitroprusside, and NG-monomethyl-L-arginine were examined in the preferred and nonpreferred limbs of eight habitual tennis players. Forearm volume, girth, and grip strength were significantly greater in the preferred limb, indicating a bilateral difference in physical condition. This was associated with an enhanced reactive hyperemic response in the preferred limb (53.5 +/- 9.4 vs. 38.8 +/- 4.7 ml.100 ml-1.min-1; P < 0.05). No differences between the limbs were evident in response to acetylcholine, sodium nitroprusside, or NG-monomethyl-L-arginine. These results suggest that exercise training enhances the peak vasodilator capacity of the vasculature without influencing basal or stimulated activity of the nitric oxide dilator system in vivo.
Green
D J
DJ
Department of Human Movement, University of Western Australia, Nedlands, Australia.
Fowler
D T
DT
O'Driscoll
J G
JG
Blanksby
B A
BA
Taylor
R R
RR
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D001808:Blood Vessels / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015444:Exercise / Q000502:physiology*; D005542:Forearm / Q000033:anatomy & histology / Q000098:blood supply*; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology; D010809:Physical Fitness / Q000502:physiology; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D013715:Tennis; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D009599:Nitroprusside; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000109:Acetylcholine