Abstract: | Well differentiated hepatoma cells in culture exhibit insulin binding and insulin effects. We have studied insulin binding in control and in H35 hepatoma cells down-regulated with insulin. H35 cells were grown in monolayers in alpha MEM. Insulin binding was measured with A14 mono 125I labelled insulin 72 h after seeding. Binding was time, temperature and pH-dependent. Receptor down-regulation was studied by exposing cells to increasing concentrations of unlabelled insulin. Monolayers preincubated with 10 micrograms/ml unlabelled insulin for 24 h showed a decrease of 65% in the number of insulin binding sites. There was no change in affinity. |