Insulin-dependent regulation of insulin receptor concentrations: a direct demonstration in cell culture.
Chronic (5-16 hr) exposure of cultured human lymphocytes to 10(-8) M insulin at 37 degrees in vitro produced a decrease in insulin receptor concentrations unaccounted for by simple occupancy of sites; acute exposure (0-2 hr) was without effect. These results reproduced observations in vivo where chronic hyperinsulinemia (e.g., 10(-8) M insulin in the circulation of obese insulinresistant hyperglycemic mice) is associated with a substantial reduction in the concentration of insulin receptors per cell, while acute hyperinsulinemia in vivo has no effect on receptor concentration. These data suggest a reciprocal relationship between insulin in the extracellular fluid and the concentration of insulin receptors per cell, which is mediated at the target cell itself by intracellular insulin-sensitive regulatory processes and directly affects target-cell sensitivity to hormone.
D001665:Binding Sites; D002478:Cells, Cultured; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007700:Kinetics; D008214:Lymphocytes / Q000378:metabolism*; D011956:Receptors, Cell Surface; D013696:Temperature
D007328:Insulin; D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface