Effect of monensin and diabetes on asialoglycoprotein degradation in rat hepatocytes.

We have studied the effects of two modulations--streptozotocin-induced diabetes in vivo, and the presence of the carboxylic proton ionophore monensin in vitro--on the degradation of 3H-asialoorosomucoid ligand in isolated rat hepatocytes. The ligand was internalized by means of a synchronous wave procedure. Diabetes was associated with a marked decrease in the amount of total degraded radioactive ligand compared to that in normal cells (3.6% and 37.3% of internalized ligand respectively, at 60 min), together with increased secretion of degradation products into the incubation medium (87% and 46.3% of the total degraded ligand was secreted by diabetic and normal cells, respectively). Monensin induced similar effects in normal cells, but had no apparent effect in diabetic cells.