THERMAL REACTIONS OF YOUNG ALBINO RATS TO INTRAPERITONEAL INJECTIONS OF ERGOTOXINE

Abstract

Ergotoxine ethanesulfonate was administered to albino rats of pre- and post-regulatory age ranges. Pre-regulatory animals (those unable to regulate body-temps. in a cold environment) responded with hypothermias while those in the post-regulatory range exhibited definite hyperthermias. Since the age range at which the reaction changed from hypo- to hyper-thermia (18-30 days) coincided with that during which rats of the same strain acquire the ability to regulate against cold and since ergotoxine is generally thought to produce hyperthermia by direct action on the hypothalamus, it was concluded that ergotoxine hyperthermia and regulatory ability are both dependent upon maturation of hypothalamic mechanisms.