The effect of diabetes on alpha2-adrenergic receptor activity in the reproductive centers of the female rat brain

We hypothesized that known diabetes-induced deficits in female rat reproduction may result in part from decreased central alpha(2)-noradrenergic receptor density or affinity. Female rats were oophorectomized and divided into 2 groups; one group received streptozocin during the operation to induce diabetes, and the other served as a nondiabetic control group. Random blood glucose levels were measured. Half the rats in each group were killed on postoperative day 10, and half were killed on postoperative day 14. Direct radioligand binding assays were performed on tissue prepared from the hypothalamus, preoptic area, and cortex of each rat. Analysis of variance was used to evaluate intergroup differences in receptor concentration or equilibrium constant. We detected no significant difference in the mean receptor concentration or equilibrium constant between the groups with and without diabetes in the hypothalamus, the preoptic area, and the cortex on postoperative day 10 or 14. Diabetes-induced impairments in female rat reproduction do not involve alterations in alpha(2)-receptor density or affinity in the hypothalamus, preoptic area, or cortex.