Endothelium-derived nitric oxide activity in forearm vessels of tennis players

Abstract

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.

Improvement in endothelial function by angiotensin converting enzyme inhibition in insulin-dependent diabetes mellitus.

“…The vasodilator response of the diabetic patients to ACh was depressed relative to that of normal subjects recruited in a recent study (20). These normal subjects were younger than the diabetic subjects, their ages averaging 28 and 43 yr, respectively.…”

“…In addition to studying the effects of ACE inhibition in the diabetic patients, their pretreatment results were compared with those of eight healthy male volunteers (28 Ϯ 2 yr) previously studied (20) and who had attended the laboratory on one occasion when forearm vascular responses to intrabrachial ACh and SNP infusion were determined. This was also undertaken during the initial session attended by the diabetic patients.…”

Repetition of Ischemic Preconditioning Augments Endothelium-Dependent Vasodilation in Humans

“…Green et al 37 reported that exercise training enhanced reactive hyperemic response, as an index of vascular structure, in the preferred arm but not in nonpreferred arm without influencing basal or ACh-induced vasodilation in tennis players. Although the discrepancy in the results of the present study may be attributable to the different stimulus, aerobic exercise and IPC, we cannot deny the possibility that repletion of IPC stimulus alters vascular structure per se.…”

Preserved contribution of nitric oxide to baseline vascular tone in deconditioned human skeletal muscle

“…It has been proposed that changes in endothelial function represent short-term adaptations to training and are eventually replaced by structural or other adaptations (Green et al 2004a). This is illustrated by the observation that the endothelial function in forearm vessels of long-term tennis players was similar in the dominant and non-dominant arm (Green et al 1996). One should take notice that these subjects played tennis for 13 h per week and that this may have resulted in concomitant training of the non-dominant arm.…”