Effect of Streptozotocin-Diabetes on In Vivo Protein Synthesis by Placenta and Liver of Mice

Abstract

Streptozotocin (200 mg/kg body weight) administered into 10-day pregnant mice induces frank diabetes. The drug-induced diabetes impairs in vivo incorporation of leucine-1-¹⁴C into proteins of maternal liver but not of placenta on the 15th day of gestation. Insulin reverses, within six hours, the diabetes as revealed by hypoglycemia and normal levels of amino acid incorporation. Injection of streptozotocin into mice on the 15th day of gestation results in inhibition of protein synthesis by maternal liver unto 8 hours after administration, unrelated to changes in the levels of blood glucose. Placental protein synthesis, however, remains unaffected. Nicotinamide (500 mg/kg body weight), injected 50 minutes prior to injection of streptozotocin, provides protection against the antibiotic-induced hyperglycemia as well as reduced incorporation of the amino acid.

Key words

Pregnant Mice - Streptozotocin - Placenta - Liver - Protein Synthesis - Insulin - Nicotinamide