On the relationship between drug-induced changes in brain amines and body temperature.

Abstract

To test the previously reported theory that changes in brain amine levels caused by drugs would lead to disturbances in body temperature regulation, the levels of 5-hydroxytryptamine and noradrenaline in the whole brain of male albino rats were determined after the animals were treated with drugs and then exposed to room temperature or elevated temperatures of 37 or 40 °C. Control experiments with untreated animals were run in parallel. The drugs used were reserpine, α-methyl-m-tyrosine (MMT), 4-chloro-N-methyl-amphetamine, 3,4-dihydroxyphenyl-L-alanine (dopa), 5-hydroxy-DL-tryptophan (5-HTP), chlorpromazine, and 2,4-dinitrophenol. The results indicated that amine levels of the brain could be increased or decreased pharmacologically without a significant interference in body temperature regulation, and also that certain drugs which interfered with body temperature regulation did so without any effect on whole-brain amine levels. It was concluded that, in the rat, there were no clear-cut relationships between whole-brain 5-hydroxytryptamine or noradrenaline levels and the ability to regulate body temperature.