Hypophysiotropic activity of histone H3 in vitro

BROWN OA,; SOSA YE,; HEREÑÚ CB,; NAUMOVICH D,; GOYA RG

PEPTIDES

Pergamon Press

Lugar: USA; Año: 2003 vol. 24 p. 671 - 678

0196-9781

Abstract To assess the effect of histone H3 on pituitary hormone secretion, rat anterior pituitary (AP) cells were used and GH, prolactin (PRL),thyrotropin (TSH), luteinizing hormone (LH) and FSH measured by radioimmunoassay (RIA). Incubation of cells with H3 (1, 6, and 30_M) stimulated the release of all five hormones in a dose-dependent manner. This effect was blocked by preincubation of H3 with an anti-H3 antibody. Incubation of AP cells with 6_MH3 in the presence of specific AP hormone secretagogues (GRP-6, thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH)) showed additive effects on hormone secretion. Pharmacological experiments suggested that calcium- and diacylglycerol- (DAG) associated pathways, but not cAMP, participate in the hypophysiotropic activity of H3. Our results confirm previous evidence that histones may act as hypophysiotropic signals. © 2003 Published by Elsevier Science Inc. 15 Keywords: Histones; Hypophysotropic activity; Pituitary cells; Second messengers; 16