Decreased availability of metabolic fuels induces anestrus in golden hamsters

Abstract

Listen

Translate article

Food deprivation inhibits ovulation and estrous behavior in golden hamsters. In experiment 1, the effects of phasic starvation (food deprivation on days 1 and 2 of the 4-day estrous cycle) depended on prior body weight and fat content. Starvation-induced anestrus, which occurs after only one cycle of phasic starvation in lean hamsters, did not occur until after three or more cycles in fat hamsters. None of the fat hamsters became anestrous until their body weights had declined to the level of lean hamsters. However, in experiment 2, we found evidence that changes in reproductive status were not signaled by any dimension of body size per se but instead by the general availability of metabolic fuels. Estrous cycles of thin hamsters were not significantly affected by food deprivation and weight loss when the hamsters were provided with either a 25% glucose solution or with vegetable shortening. In experiment 3, simultaneous pharmacological reduction of both fatty acid oxidation and glycolysis inhibited estrous cycles in hamsters fed ad libitum. Estradiol treatment restored estrous behavior, but not ovulation, in food-deprived, lean hamsters and in hamsters in which both fatty acid oxidation and glycolysis were reduced. Decreased availability of utilizable metabolic fuels may inhibit follicular development, which may in turn lead to circulating estradiol levels that are insufficient to stimulate estrous behavior.