Changes in insulin receptor concentration in rat fat cells following treatment with the gestagens clomegestone acetate and cyproterone acetate.

Specific insulin receptors were measured in isolated fat cells of rats after treatment with clomegestone acetate. Under conditions when peripheral insulin insensitivity was observed, the number of insulin receptors was simultaneously reduced. A similar though smaller decrease in insulin receptor concentration was seen in rats after treatment with cyproterone acetate, a compound which did not cause insulin resistance. It is concluded that the gestagenic compounds tested decrease insulin receptor concentration. Only drastic reduction of the number of binding sites results in significant perturbations of carbohydrate metabolism.