Fetal rat hyperinsulinism and hyperglucagonism: effects on hepatic ketogenesis, lipogenesis, and gluconeogenesis.

To study the direct effects of hyperglucagonism and hyperinsulinism (both with glucose excess) on fetal intermediary metabolism, rat liver explants from 19-day-gestated fetuses were maintained in culture for 48 h. The liver cubes were exposed to 0, 250, or 500 mU/ml porcine insulin or 5 micrograms/ml glucagon. In addition, lipogenesis from 3H2O was cumulated throughout the 48 h. Chronic hyperinsulinism in the fetal rat doubled hepatic lipogenesis and curtailed hepatic gluconeogenesis and ketogenesis by 80% and 50%, respectively. Chronic hyperglucagonism was without effect; however, the fetal liver did yet respond to 1 mM (Bu)2cAMP.