Interleukin 1 potentiates agonist-induced secretion of beta-endorphin in anterior pituitary cells.
Interleukin 1 (IL-1) has been shown to potentiate the release of beta-endorphin induced by secretagogues, including corticotropin releasing factor (CRF) and phorbol ester (TPA), in the mouse AtT-20 pituitary tumor cell line (Fagarasan et al., PNAS, 1989, 86, 2070-2073). In cultured rat anterior pituitary cells, pretreatment with IL-1 caused only a small increase in beta-endorphin release but significantly potentiated CRF-and vasopressin-stimulated beta-endorphin secretion. Vasopressin stimulates the secretion of beta-endorphin in normal pituitary cells but not in AtT-20 cells. However, treatment of AtT-20 cells with IL-1 induced the expression of vasopressin-mediated beta-endorphin release; this effect of IL-1 was reduced after depletion of protein kinase C by prolonged treatment with TPA. The enhancement of CRF-stimulated beta-endorphin release by IL-1 was also reduced in AtT-20 cells after depletion of protein kinase C, and after treatment with staurosporine. These findings indicate that treatment with IL-1 amplifies receptor-mediated responses to the major physiological secretagogues in normal corticotrophs, and initiates a secretory response to vasopressin in AtT-20 cells.
Făgărăsan
M O
MO
Laboratory of Cellular Biology, National Institutes of Mental Health, Bethesda, MD 20892.
Axelrod
J
J
Catt
K J
KJ
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D005260:Female; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D010703:Phorbol Esters / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D019311:Staurosporine; D014667:Vasopressins; D001615:beta-Endorphin / Q000378:metabolism*
D000470:Alkaloids; D007375:Interleukin-1; D010703:Phorbol Esters; D014667:Vasopressins; D001615:beta-Endorphin; D003346:Corticotropin-Releasing Hormone; D011493:Protein Kinase C; D019311:Staurosporine