Effects of progesterone and 17-beta-oestradiol treatments on the pancreatic B cell castrated female rats. Biochemical variations.

The biochemical effects of progesterone and/or oestradiol treatments on castrated female rats have been compared to those of control olive-oil injections. 1. The steroid treatments used produced physiological concentrations of the two hormones in peripheral plasma, comparable to those obtained during pregnancy. 2. Glycemia remains within a normal range for all the treatments. 3. Circulating immunoreactive insulin (IRI) increases in the steroid-treated rats and the values reach those of the pregnant animals. 4. It was concluded that the biochemical modifications that occur during the steroid treatment (especially with the combined treatment) are quite comparable to what happens during pregnancy and explain, at least in part, the altered carbohydrate and lipid metabolism, and the hyperactivity in the B cell, resulting in an increased insulin secretion.