INFLUENCE OF THE RATE OF SWEATING ON THE INHIBITORY DOSE OF ATROPINE.
Technical rept., Jun-Dec 65,
EDGEWOOD ARSENAL MD
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Before the injection of atropine, sweating in resting men, measured by continual weighing, increased with environmental temperature from 2 gmmin at 35C to 13 gmmin at 52C. Atropine sulfate was infused intravenously at rates between 0.01 and 0.10 mgmin after rapid intravenous injections of from 0 to 0.5 mg. Larger rates of infusion were required to inhibit sweating at 52 than at 35C. The accumulated dose y, in micrograms per kilogram required to inhibit sweating by one-half, increased with the control rate of sweating x in grams per square meter minute according to the equation y 2.6 plus or minus 0.3 0.76 plus or minus 0.15 x. The rapid recovery after the end of the infusion and the failure of the inhibition to progress as the dose accumulated at slow infusion rates suggested that the effect of atropine was being opposed by an added stimulus generated by the increase in skin temperature during the period of reduced sweating. The theory of a surmountable antagonism between atropine and endogenous acetylcholine at receptor sites on the sweat gland appears to explain the results. Author
- Anatomy and Physiology