Insulin-receptor turnover and down regulation in hepatocytes.
Receptor-mediated degradation of 125I-insulin by hepatocytes was studied to evaluate its role in down-regulation of insulin receptors in liver. The amount of 125I-insulin bound to the cell surface was found to remain relatively constant during times of active insulin degradation over a wide range of insulin concentrations, even in the presence of cycloheximide. This observation, as well as other considerations discussed in the text, suggest that down-regulation of insulin receptors is not an inevitable consequence of receptor-mediated degradation in insulin, but rather represents a distinct metabolic effect of the hormone.
D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051381:Rats; D011972:Receptor, Insulin / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology
D007328:Insulin; D003513:Cycloheximide; D011972:Receptor, Insulin; D014357:Trypsin