Human Fetal Adrenal Cell Responses to ACTH and Pituitary Extracts

Abstract

Human fetal adrenal tissues were studied in dispersed cell suspensions prepared by collagenase digestion;triplicate aliquots were incubated for 2 hours; control cells were compared to cells stimulated with 3 dilutions of ACTH and compared to responses from cells stimulated with 3 dilutions of 2 fractions prepared from human pituitaries (“A” and “B”). Crude fraction A contained FSH, LH and TSH; B contained ACTH, MSH and other peptides. 4 specimens with single adrenal weights of 128 mg, 243 mg, 488 mg and 915 mg were studied. Incubation medium was analyzed for dehydroepiandrosterone sulfate (DHAS) and corticoids (C). Unstimulated C secretion was similar in all weights (137 ± 63 pg/ml/100,000 cells); DHAS secretion was variable but increased with increasing size (16 ng/ml to 56 ng/ml/100,000 cells). ACTH caused dose-related proportionate increases in both DHAS and C in all; pit. frx “A” gave greater DHAS responses than ACTH in the 243 mg adrenal: DHAS:C ratio of 233:1 for ACTH and 7051:1 for “A.” However, this was not found in the more mature 915 mg gland (311:1 for ACTH and 191:1 for “A”). “B” reacted like ACTH. We conclude that (a) the developing fetal adrenal shows changing responses to different stimuli, perhaps reflecting changes in receptor response, number or discrimination, and (b) pituitary extract “A” may contain an androgen stimulator effective at variable stages of development.