Plasma insulin response and food intake in pseudopregnant rats

1. Plasma insulin response to an intravenous glucose injection was measured in anaesthetised pseudopregnant and non-pregnant rats. Food intakes and body composition were also compared in pseudopregnant and non-pregnant animals. 2. The insulin responses and food intakes were greater in the pseudopregnant group. 3. Pseudopregnancy increased the fat-free dry weight of the animals and there was a tendency for the proportion of fat to be increased. 4. The results provide further evidence to indicate that in the rat progesterone plays a significant part in increasing insulin secretion during pregnancy.