Insulin binding to erythroblastic leukemic cells is decreased by insulin and increased by amino acids

Erythroblastic leukemic cells incubated in media supplemented with high amino acid concentrations subsequently bound 55.5% more [¹²⁵I]insulin than cells incubated in low amino acid media. Cycloheximide (1 μg/ml) abolished this effect. Incubation of cells with physiological (100 μU/ml) doses of insulin in low amino acid media decreased insulin binding by 34.7%. In high amino acid media the same dose of insulin decreased insulin binding by 33% compared to supplemented media without insulin but increased binding by 22.5% compared to basal media without insulin. The data suggest that amino acids or specific amino acids may exert a regulatory influence on insulin receptor homeostasis.