Atropine-Induced Cutaneous Vasodilation Decreases Body Temperature during Exercise

摘要

Systemic atropine enhances forearm cutaneous blood flow (FBF) but depresses forearm sweating (m sub s) in warm environments, as previously shown in our laboratory. To further examine thermoregulatory consequences of this increased FBF, four healthy males were studied during 30 minutes of seated exercise. Esophageal (T sub es) and mean skin (T sub sk) temperatures, m sub s metabolism (M), heart rate (HR) and FBF were measured during control and following 2 mg (im) atropine. All eight skin temperatures increased with atropine which implies widespread cutaneous vasodilation. The enhanced sensible heat loss with atropine during constant intensity exercise caused T sub es to decrease, resulting in a further significant m sub s depression. The decreased central drive did not result in peripheral vasoconstriction, suggesting that the dilation was peripherally controlled and non-responsive to the thermoregulatory controller.