Binding of 125I-human growth hormone to specific receptors in human cultured lymphocytes. Characterization of the interaction and a sensitive radioreceptor assay.

摘要: Abstract The interaction of human growth hormone with lymphocytes from an established culture (IM-9) was studied using 125I-human hormone. binding rapid; at 0.1 nm a steady state observed in 90 min 30°. Bound labeled dissociated rapidly by addition excess unlabeled Binding to cultured relatively insensitive alterations the pH and concentrations Ca2+, Mg2+, or EDTA. At 30° there very little degradation specific receptor sites. Tryptic digestion destroyed capacity cells bind IM-9 bound all preparations but not unrelated hormones nonprimate hormones. inhibited 10 14% 1 2 ng per ml 50% 30 40 ml, well within range vivo. Analysis data revealed single order sites affinity constant 1.3 x 109 m-1 about 4000 cell. Numerous were assayed use this system as immunoassay bioassay potencies determined radioreceptor assay correlated more closely than radioimmunoassay.