Concomitant secretion of Y-MSH with ACTH and beta-endorphin in humans.
Using a specific radioimmunoassay for gamma-melanotropin (gamma-MSH), one of the predicted fragments in the amino-terminal portion of the adrenocorticotropin(ACTH)-beta-lipotropin (beta-LPH) precursor, gamma-MSH-like immunoreactivity (gamma-MSH-LI) was detected in human plasma from 4 of 5 patients with Addison's disease and 2 of 3 patients with Nelson's syndrome. None of the normal subjects or patients with Cushing's disease showed detectable concentrations (more than 150 pg/ml) of gamma-MSH-LI. gamma-MSH-LI was secreted concomitantly with ACTH-like immunoreactivity (ACTH-LI) and beta-endorphin-like immunoreactivity (beta-endorphin-LI) in response to insulin-induced hypoglycemia and the administration of lysine-vasopressin. Conversely, intravenous injection of cortisol lowered plasma concentrations of gamma-MSH-LI concomitantly with those of ACTH-LI and beta-endorphin-LI. Gel chromatographic studies of the plasma extracts showed a single peak of gamma-MSH-LI near the elution position of human beta-LPH. These results suggest that gamma-MSH-LI in human plasma is present as a big form and that this big gamma-MSH is secreted concomitantly with ACTH and beta-endorphin.
D000224:Addison Disease / Q000097:blood; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D003480:Cushing Syndrome / Q000097:blood; D004723:Endorphins / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone; D007328:Insulin; D008236:Lypressin; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D009347:Nelson Syndrome / Q000097:blood; D012016:Reference Values
D004723:Endorphins; D007328:Insulin; D008236:Lypressin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones; D006854:Hydrocortisone