Type beta transforming growth factor is a potent modulator of differentiated adrenocortical cell functions.
Whereas TGF-beta exhibited no detectable effect on DNA synthesis, it was found to exert a striking inhibitory effect on the steroidogenic activities of bovine adrenocortical cells in culture. Basal, as well as ACTH- and angiotensin II- activated adrenocortical cortisol productions were inhibited in a time and dose-dependent manner following TGF-beta treatment. Half-maximum inhibition of ACTH- and AII-activated steroidogenesis was observed with TGF-beta concentrations of 0.40 and 0.12 ng/ml, respectively. This effect was half maximal after 6 hours of cell exposure to optimally effective TGF-beta concentrations (1 ng/ml) and reached a plateau after 12-15 hours, resulting in an average 60% inhibition in the steroidogenic response to ACTH and 90% in the case of AII. Supply of different exogenous steroid substrates to support steroidogenesis in adrenocortical cells pointed to a marked loss in steroid-17 alpha hydroxylase activity as a major alteration following TGF-beta treatment. TGF-beta thus appears as a potent modulator of differentiated adrenocortical cell functions in vitro; in this regard it may play a significant role in the development and the regulation of adrenal cortex in vivo.
D006907:17-alpha-Hydroxypregnenolone / Q000494:pharmacology; D019326:17-alpha-Hydroxyprogesterone; D000302:Adrenal Cortex / Q000187:drug effects*; D000305:Adrenal Cortex Hormones / Q000096:biosynthesis; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D004261:DNA Replication / Q000187:drug effects; D006908:Hydroxyprogesterones / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D011284:Pregnenolone / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013256:Steroids; D015291:Transforming Growth Factors
D000305:Adrenal Cortex Hormones; D006908:Hydroxyprogesterones; D010455:Peptides; D013256:Steroids; D000804:Angiotensin II; D006907:17-alpha-Hydroxypregnenolone; D011374:Progesterone; D019326:17-alpha-Hydroxyprogesterone; D011284:Pregnenolone; D015291:Transforming Growth Factors; D000324:Adrenocorticotropic Hormone; D013254:Steroid 17-alpha-Hydroxylase