Heat Exchange through Cutaneous Vasodilation After Atropine Treatment in Two Environments
Abstract
This report summarizes two tightly controlled laboratory studies in which the thermo-regulatory effects of an intramuscular injection of atropine sulfate (2 mg) were compared with a placebo injection of sterile saline during two environmental conditions. Four subjects were tested in each environmental condition (22 C or 30 C) during seated cycle exercise at a moderate exercise intensity (55% VO2 peak). Esophageal temperature (T), mean weighted skin temperature (Tsk), and forearm sweating rate (ms) were continuously measured during 30 minutes of rest and 35 minutes of exercise. Skin blood flow (FBF) from the forearm was measured twice each minute by venous occlusion plethysmography. The expected decrease in whole body and local sweating rate (-60%) occurred in both environments in the atropine treated subjects. The increased skin blood flow compensated for the suppression in sweating increasing dry heat loss in the atropine experiments. The atropine-induced vasodilation was widespread as skin temperatures increased at all sites measured. These results suggest that the peripheral modification of cutaneous blood flow which occurs in atropine treated subjects is sufficient to alter heat exchange in both warm and cool environments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1987
- Accession Number
- ADA187730
Entities
People
- Lou A. Stephenson
- Margaret A. Kolka
Organizations
- United States Army Research Institute of Environmental Medicine