EFFECT OF FASTING ON INSULIN SENSITIVITYA

Abstract

Doses of insulin which cause pronounced hypoglycemia and shock in rats fasted for shorter or longer periods have relatively little effect after about 48 hrs. of starvation. In fact in some cases, the blood sugar may actually rise following treatment with this hormone. Since fasted animals are used for most expts. concerned with the action of insulin, it is believed that this transitory change in insulin sensitivity deserves attention. The period of maximum insulin resistance precedes the period of "fasting hyperglycemia" in the rat, yet it is posisble that the spontaneous transitory increase in blood sugar and the temporary insulin resistance may be correlated phenomena. The possible physiological mechanism responsible for these changes in the carbohydrate metabolism of fasting animals are considered.