Regulation of baboon fetal adrenal androgen production by adrenocorticotropic hormone, prolactin, and growth hormone

Abstract

Factors other than adrenocorticotropic hormone (ACTH) are thought to infuence fetal adrenal steroidogenesis during primate pregnancy. Therefore, we determined the effects of prolactin (Prl), growth hormone (GH), and human chorionic gonadotropin (hCG) as well as ACTH on steroid secretion by collagenase-dispersed baboon fetal adrenal cells. Adrenal glands were obtained from seven baboon (Papio anubis) fetuses following cesarean section at Day 100-107 of gestation (term=day 184). Tissue was minced with a fine scissors and cells were dispersed with 0.2% collagenase, then washed with Medium 199 containing penicillin/streptomycin. Cells (0.5 x 104) were placed in 4 ml Medium 199 with or without 10 nmol ovine Prl, ovine GH, or ACTH, or 50 nmol hCG. After 18 h incubation (37°C), cells were separated by centrifugation and the quantities of cortisol (F), dehydroepiandrosterone (DHA), and DHA-sulfate (DHAS) secreted into the medium were determined. In controls, DHA secretion [224 ± 96 ng/(24 h·105) cells] was greater (P<0.05) than that of DHAS (20 ± 12) and F (14 ± 12). Adrenocorticotropic hormone, Prl, and GH stimulated (P<0.05) DHA secretion by 370% ± 71%, and 292% ± 73%, respectively; hCG was not effective. Due primarily to the relatively low secretion rates, DHAS and F secretion were not altered by hormonal treatment. Moreover, addition of 20 nmol progesterone to the medium in the presence or absence of ACTH did not influence F production. These findings indicate that the baboon fetal adrenal at midgestation does not utilize placental progesterone for F synthesis. We conclude that Prl, GH, and ACTH modulate baboon fetal adrenal DHA secretion without altering the production of F and DHAS at midgestation. Therefore, we suggest that at midgestation there is probably more than one factor regulating baboon fetal adrenal androgen secretion.