Reciprocal changes, caused by insulin and glucagon, of adipose tissue lipoprotein lipase in rats in vitro

Abstract

Effects of insulin and glucagon on lipoprotein lipase activity in rat adipose tissue were studied in vitro. Adipose tissue from normal or streptozotocin-diabetic rats was incubated in Krebs-Ringer bicarbonate buffer for 60 min at 38 degrees C in the presence of heparin and lipoprotein lipase released from the tissue into the incubation medium was measured. Diabetic rats showed markedly low activities of adipose tissue lipoprotein lipase. Insulin (500 microU/ml) increased lipoprotein lipase activity in adipose tissue from diabetic rats. Glucagon (500 pg/ml), on the other hand, decreased the enzyme activity in normal rat adipose tissue. The results indicate that insulin and glucagon cause reciprocal changes of lipoprotein lipase activity in rat adipose tissue.