THE EFFECT OF FORCED EXERCISE ON BODY TEMPERATURE AND AMPHETAMINE TOXICITY

¹ Department of Pharmacology, School of Medicine, Loma Linda University, Loma Linda, California

The rise in body temperature of isolated mice whose motor activity is increased by forced excersice is as great as that of aggregated animals and both are significantly greater (P [unknown] 001) than in nonexercised isolated animals receiving the same dose of amphetamine or in untreated mice forced to exercise. Thus hyperthermia, and the associated mortality in amphetamine poisoning in mice, appears to be due to a combination of increased motor activity and impaired temperature regulation.

Since the increase in toxicity of amphetamine in isolated mice forced to exercise is as great as that of aggregation, it is suggested that "aggregation effect" of amphetamine is primarily due to increase in body temperature caused by an increase in motor activity. The protection offered by chlorpromazine to aggregated mice is probably due both to diminished sensory perception which prevents increased motor activity, and to its hypothermic effect.