The effects of ACTH 1-17 on GH secretion in vitro.
Recently we demonstrated that ACTH 1-17 infusion in normal subjects is able to stimulate growth hormone (GH) secretion. In order to study the mechanism by which ACTH 1-17 induces this hormonal secretory pattern, we examined the effects of ACTH 1-17 addition to primary cultures of rat anterior pituitary cells and of two human pituitary adenomas (a mixed GH- and PRL-secreting adenoma and a prolactinoma) on GH and PRL secretion. Normal rat pituitary cells responded to rGRF with a dose-dependent increase of rGH: ACTH 1-17 induced a slight not significant increase of rGH secretion even at micromolar concentrations. Furthermore no additive effect of ACTH 1-17 on rGRF-stimulated GH release was observed. No significant stimulatory effect was also documented in the human tumors studied. These results suggest that the GH releasing activity of ACTH 1-17 observed in vivo is mediated via a direct action on CNS.
Ceda
G P
GP
Institute of Clinica Medica Generale, University of Parma, Italy.
Denti
L
L
Valenti
G
G
D000236:Adenoma / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D010446:Peptide Fragments; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; C028238:ACTH (1-17)