Effects of Body Temperature and of Pentobarbital on Brain Damage Produced by Insulin Shock. ∗

Abstract

Discussion and Conclusions. The protective action of cooling during insulin shock has been reported previously. 2 These experiments demonstrate that when the body temperature is prevented from falling, the time necessary to produce damage is considerably shortened, and the degree of brain damage is greater. This is to be expected since the higher the temperature, the higher the metabolic rate and the greater the oxygen need of the brain. When the body temperature is kept at normal levels during insulin shock it would seem that a relatively greater degree of tissue anoxia results than when the body temperature is permitted to fall, due to the greater need of oxygen at higher temperatures. This may be a factor responsible for the prolonged comas and accidents frequently occurring during insulin shock therapy, since the drop in body temperature in humans is not as great as that which occurs in cats. Dogs also are found to be resistant to the hypothermic action of insulin. In this laboratory, it has been found that considerably shorter periods are necessary to produce brain damage in this animal than is needed for cats. In fact, brain damage has been produced in the dog without it showing the characteristic symptoms of the 4th phase. 7