Thyroidal dependence of glucose-induced insulin secretion in starved rats

To elucidate the possible role of thyroid hormone in insulin secretion during starvation, we investigated the glucose-induced insulin release in T3-administered starved rats. The rats were fasted for 72 hr, and one-half of the starved rats were administered subcutaneous 3,5,3'-triiodothyronine (5.0 micrograms/kg) at 12, 36, and 60 hr. In an intravenous glucose (0.5 g/kg) infusion test, insulin response was significantly lower in starved rats than in fed controls. This decreased insulin was restored by T3 administration. These results suggest the thyroidal dependence of insulin response to glucose in short-term starvation.