Effect of progesterone on lipid metabolism in the intact rat.

Females rats implanted with progesterone gained weight more rapidly than control animals and had an increased proportion of total body fat. Restriction of food intake to control levels demonstrated that the weight changes was not dependent on increased energy intake. Serum concentrations of cholesterol, phospholipid and non-esterified fatty acid were raised in hormone-treated rats but triglyceride levels were normal. Endogenous production of triglyceride was also unchanged. Total postheparin lipoprotein lipase activity was increased in the plasma of progesterone-treated rats largely due to increased release of the extrahepatic protamine sulphate-labile fraction. The basal rate of lipogenesis was also increased in adipocytes isolated from hormone-treated rats as was the insulin-stimulated rate of oxidation of[1-14 C]glucose. Basal and adrenaline-stimulated rates of fat cell lipolysis were, however, unchanged by treatment with progesterone.