Enhanced endothelium-dependent vasodilatation in human skin vasculature induced by physical conditioning

Abstract

Functional alterations to the endothelial cells of the vascular system may contribute to the improved circulatory performance induced by physical conditioning. We evaluated microvascular reactivity to iontophoretic application of acetylcholine (ACh) and sodium nitroprusside (SNP) through the skin and blood perfusion measurements in the same area using laser Doppler flowmetry. Whereas ACh acts on smooth muscle cells of the vascular system via the production of vasodilator substances from the endothelium, SNP is an endothelium-independent vasodilator acting on vascular smooth muscle cells directly. The study was performed using two groups of subjects with different levels of aerobic endurance, long distance runners competing at national level (n = 9) and controls (n = 9). The subjects were tested for 40 min on a treadmill before and after an exercise test at 80% of their maximal oxygen uptake. During stimulation by ACh cutaneous perfusion increased to a higher level in the athletes than in the controls (overall P<0.05), whereas an acute period of exercise abolished this difference (overall P>0.6). There was no significant difference between the athletes and the controls with respect to the SNP-induced increase in cutaneous perfusion either before (P>0.9) or after (P>0.9) exercise. The higher cutaneous perfusion responses to stimulation with ACh in the athletes than in the controls may support the hypothesis that regular exercise modifies the responsiveness of the cutaneous endothelium. The difference in ACh-induced perfusion and in unstimulated forearm perfusion between the two groups was present only at rest. This finding indicated that mechanisms were introduced during exercise, which compensated for the lower endothelial sensitivity to stimulation in the controls at rest.

Impaired microvascular endothelial function is restored by acute lower-limb exercise in post-surgical varicose vein patients

“…No such changes were observed in the control group (Fig. 3 lower panel), which is consistent with some (Colberg et al, 2006;Rossi et al, 2002), but not all (Kvernmo et al, 1998), previous studies. As a result, the impairment of microvascular endothelial vasodilator function that was observed in the patients before exercise was abolished by acute lower-limb exercise, such that there was no difference in the peak perfusion responses to ACh between patients and controls.…”

“…As a result, the impairment of microvascular endothelial vasodilator function that was observed in the patients before exercise was abolished by acute lower-limb exercise, such that there was no difference in the peak perfusion responses to ACh between patients and controls. Finally, there was no effect of acute exercise on SNP responsiveness in either group or position, which is consistent with the literature (Kvernmo et al, 1998;Rossi et al, 2002). These findings suggest that moderate-intensity lowerlimb aerobic exercise is an effective stimulus for improving microvascular endothelial function in postsurgical varicose vein patients; however, further research is needed to clarify the clinical relevance of these findings, i.e., whether chronic exercise training reduces recurrence rates for varicose veins and/or venous ulcers.…”

Effect of a Single Bout of Prior Moderate Exercise on Cutaneous Perfusion in Type 2 Diabetes

“…Endothelium-dependent dilation in skin vasculature is enhanced by moderate exercise training and reversed by detraining (17), and trained athletes have enhanced endothelium-dependent vasodilatation in skin vasculature at rest (18). These studies suggest that exercise modifies the responsiveness of the cutaneous endothelium, although we found such differences in our subjects to be abolished by a bout of maximal exercise (3).…”

Cardiovascular Adaptations to Exercise Training

“…These systemic adaptations may primarily be associated with the training-induced increase in plasma volume, as plasma volume is a determining factor for cutaneous perfusion (138,204). The local responsiveness of the skin, for example, with local heating (360) or in response to ACh (238,450), is also improved by exercise training, an effect that may be due to a greater contribution by NO and prostaglandins (92,360), at least in part, induced by repetitive increases in shear stress (308).…”