A 3-month aerobic exercise training intervention reduced the vasodilator response to BQ-123 by ~25% and increased forearm blood flow responses to acetylcholine by ~35% in overweight and obese adults.
Does a 3-month aerobic exercise training intervention reduce endothelin-1-mediated vasoconstrictor tone in previously sedentary overweight and obese adults?
Regular aerobic exercise reduces endothelin-1-mediated vasoconstrictor tone in previously sedentary overweight and obese adults, which is an important mechanism underlying exercise-induced improvements in endothelium-dependent vasodilator function.
New Findings What is the central question of this study? Does aerobic exercise training reduce endothelin‐1 (ET‐1)‐mediated vasoconstrictor tone in overweight/obese adults? And, if so, does lower ET‐1 vasoconstriction underlie the exercise‐related enhancement in endothelium‐dependent vasodilatation in overweight/obese adults? What is the main finding and its importance? Regular aerobic exercise reduces ET‐1‐mediated vasoconstrictor tone in previously sedentary overweight/obese adults, independent of weight loss. Decreased ET‐1 vasoconstriction is an important mechanism underlying the aerobic exercise‐induced improvement in endothelium‐dependent vasodilator function in overweight/obese adults. Endothelin‐1 (ET‐1)‐mediated vasoconstrictor tone is elevated in overweight and obese adults, contributing to vasomotor dysfunction and increased cardiovascular disease risk. Although the effects of habitual aerobic exercise on endothelium‐dependent vasodilatation in overweight/obese adults have been studied, little is known regarding ET‐1‐mediated vasoconstriction. Accordingly, the aims of the present study were to determine the following: (i) whether regular aerobic exercise training reduces ET‐1‐mediated vasoconstrictor tone in overweight and obese adults; and, if so, (ii) whether the reduction in ET‐1‐mediated vasoconstriction contributes to exercise‐induced improvement in endothelium‐dependent vasodilatation in this population. Forearm blood flow (FBF) in response to intra‐arterial infusion of selective ET A receptor blockade (BQ‐123, 100 nmol min −1 for 60 min), acetylcholine 4.0, 8.0 and 16.0 μg (100 ml tissue) −1 min −1 in the absence and presence of ET A receptor blockade and sodium nitroprusside 1.0, 2.0 and 4.0 μg (100 ml tissue) −1 min −1 were determined before and after a 3 month aerobic exercise training intervention in 25 (16 men and nine women) overweight/obese (body mass index 30.1 ± 0.5 kg m −2 ) adults. The vasodilator response to BQ‐123 was significantly lower (∼25%) and the FBF responses to acetylcholine were ∼35% higher after exercise training. Before the exercise intervention, the co‐infusion of acetylcholine plus BQ‐123 resulted in a greater vasodilator response than acetylcholine alone; however, after the exercise intervention the FBF response to acetylcholine was not significantly increased by ET A receptor blockade. These results demonstrate that regular aerobic exercise reduces ET‐1‐mediated vasoconstrictor tone in previously sedentary overweight and obese adults. Moreover, decreased ET‐1‐mediated vasoconstriction is an important mechanism underlying the aerobic exercise‐induced improvement in endothelium‐dependent vasodilator function in overweight/obese adults.
Dow et al. (Mercredi,) ont mené une autre étude chez des personnes en surpoids et obèses (n=25). L'entraînement aérobie par rapport à la ligne de base (avant l'intervention d'exercice) a été évalué sur le flux sanguin de l'avant-bras en réponse au blocage des récepteurs ETA (BQ-123) et à l'acétylcholine. Une intervention d'entraînement aérobie de 3 mois a réduit la réponse vasodilatatrice au BQ-123 d'environ 25 % et a augmenté les réponses du flux sanguin de l'avant-bras à l'acétylcholine d'environ 35 % chez les adultes en surpoids et obèses.