Studies on steroid hormone receptors (5alpha-dihidrotesterone, estradiol, and dexamethasone) in cultured human fibroblasts and amniotic fluid cells.

Cultured human fibroblasts and amniotic fluid cells (AF cells) were examined for the presence of steroid hormone receptors. In both cell types, the androgen (DHT) or glucocorticoid (dexamethasone) receptor was detected, but not the estrogen receptor. Binding parameters in fibroblasts were: for androgen: KD = 3.7 X 10(-9) M, Bmax = 13 fmol/mg; for dexamethasone: KD = 4.5 X 10(-9) M, Bmax = 120 fmol/mg. Binding parameters in AF cells were: for androgen: KD = 4 X 10(-9) M, Bmax = 8 fmol/mg; for dexamethasone: KD = 1.9 X 10(-8) M, Bmax = 375 fmol/mg. Cultured cells derived from the gonads (of a patient with 17beta-ketosteroid reductase deficiency) seem to have more receptors than cells from extragenital body parts (Bmax = 21 fmol). With the aid of gel chromatography, the molecular weight of the androgen receptor was estimated to be 30-40 000D.