Aviat Space Envir Md
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Aviat Space Envir Md · Jan 1989
Clinical Trial Controlled Clinical TrialHeat exchange through cutaneous vasodilation after atropine treatment in a cool environment.
This report summarizes a tightly controlled laboratory study in which the thermoregulatory effects of an intramuscular injection of atropine sulfate (2 mg) were compared with a placebo injection of sterile saline during exposure to a cool environment. Four subjects were tested during seated cycle exercise at a moderate exercise intensity (55% Vo2 peak) at an ambient temperature of 22 degrees C (37% relative humidity; ambient water vapor pressure 1.0 kPa). Esophageal temperature (Tes), mean weighted skin temperature (Tsk), and forearm sweating rate (ms) were continuously measured during 30 min of rest and 35 min of exercise. ⋯ By 25 min of exercise. FBF was 98% (p less than 0.05) greater after atropine treatment. These results show that the peripheral modification of cutaneous blood flow which occurs in atropine-treated subjects is sufficient to markedly alter heat exchange in a cool environment.