Receptors for insulin-like peptides (ILAs) in rat reticulocytes and erythrocytes.
Rat reticulocytes possess receptors for an insulin-like somatomedin peptide ILAs. At 20 C, pH 7.4 and 10(8) cells per ml, the binding of 125I-ILAs reached a steady-state at 120 min. Binding was partially reversible at 20 C and totally reversible at 37 C. Insulin did not compete with ILAs at concentrations as high as 10 microgram/ml. Insulin-like growth factor II (IGF II) competed with the same potency as ILAs itself, while insulin-like growth factor I (IGF I) was five times less potent. The optimum pH for 125I-ILAs binding was 8.5. Mature erythrocytes possessed seven times less binding sites than reticulocytes. These data suggest that the somatomedins might mediate the effect of growth hormone on erythropoiesis.
D000818:Animals; D004912:Erythrocytes / Q000378:metabolism*; D008297:Male; D010659:Phenylhydrazines / Q000494:pharmacology; D051381:Rats; D011972:Receptor, Insulin / Q000378:metabolism*; D012156:Reticulocytes / Q000378:metabolism*; D013997:Time Factors
D010659:Phenylhydrazines; D011972:Receptor, Insulin