Open AccessCorticotropin-releasing factor stimulates phospholipid methylation and corticotropin secretion in mouse pituitary tumor cells.
Author(s) -
Vivian Hook,
Seymour Heisler,
Julius Axelrod
Publication year - 1982
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.79.20.6220
Subject(s) - phospholipid , medicine , endocrinology , phosphatidylethanolamine , adrenocorticotropic hormone , methylation , acth receptor , anterior pituitary , chemistry , phosphatidylcholine , secretion , biology , biochemistry , hormone , membrane , gene
The 41-residue synthetic ovine corticotropin-releasing factor (CRF; corticoliberin) has been shown to stimulate release of corticotropin (adrenocorticotropic hormone; ACTH) and beta-endorphin from AtT-20/D16-16 mouse pituitary tumor cells. Phospholipid methylation of phosphatidylethanolamine to phosphatidylcholine with S-adenosylmethionine as methyl donor has been suggested as a possible membrane transduction mechanism for some receptor-induced events. CRF increased phospholipid methylation in pituitary tumor cells at concentrations that also stimulated immunoreactive ACTH secretion, and both processes increased linearly and in parallel with time. The methionine sulfoxide derivative of CRF was less potent than CRF was in stimulating both phospholipid methylation and hormone secretion, and the COOH-terminal free acid analogue of CRF had no effect on either process. CRF-induced increases in phospholipid methylation and ACTH secretion were reduced when cells were treated with the phospholipid methyltransferase inhibitors 3-deazaadenosine and L-homocysteine thiolactone. These CRF-stimulated effects were also blocked by the glucocorticoid dexamethasone. It is suggested that phospholipid methylation may be a CRF receptor-mediated event associated with ACTH release in pituitary tumor cells.