Enhanced dilation to acetylcholine in athletes is associated with
lower plasma cholesterol.
Kingwell, Bronwyn A., Binh Tran, James D. Cameron, Garry L. Jennings,
Anthony M. Dart.
Alfred and Baker Medical Unit, Alfred Hospital and Baker Medical
Research Institute
APStracts 2:0519H, 1995.
We investigated a change in vascular reactivity as a potential
adaptive mechanism to chronic exercise. The study c onsisted of two
separate protocols with ten male athletes and te n age matched
sedentary male control subjects participating in each. Protocol 1
investigated forearm blood flow responses to i ntra arterial
infusions of acetylcholine and sodium nitroprus side using venous
occlusion plethysmography. Protocol 2 used i dentical techniques to
study responses to noradrenaline, angi otensin II and NG-monomethyl
L-arginine (L-NMMA). The percent age reduction in forearm vascular
resistance to acetylcholine was significantly greater in the athletic
compared to the seden tary group (Multivariate analysis of variance
for repeated mea sures, P=0.03). Covariance analysis suggested that
the lower t otal cholesterol level of the athletic group (P=0.03) may
contr ibute to their enhanced responsiveness to acetylcholine. Ther e
were no differences between athletic and sedentary groups in t he
forearm vascular resistance responses to noradrenaline, an giotensin
II, sodium nitroprusside or L-NMMA. These data suppo rt the
hypothesis that long term endurance training is associat ed with
enhanced endothelium dependent dilator reserve due to a ltered
lipoprotein levels in athletes. This finding may have th erapeutic
application in conditions of elevated cholesterol a nd impaired
vasodilator capacity including hypertension, hyp ercholesterolemia,
atherosclerosis and cardiac failure.
Received 14 August 1995; accepted in final form 8 November 1995.
APS Manuscript Number H760-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95