Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10956188 | Molecular and Cellular Endocrinology | 2014 | 9 Pages |
Abstract
Somatostatin is the most effective inhibitor of GH release, and GHRH was recently identified as one of the primary GH-releasing factors in teleosts. In this study, we analyzed the possible intracellular transduction pathways that are involved in the mechanisms induced by SRIF and GHRH to regulate GH release. Using a pharmacological approach, the blockade of the PLC/IP/PKC pathway reversed the SRIF-induced inhibition of GH release but did not affect the GHRH-induced stimulation of GH release. Furthermore, SRIF reduced the GH release induced by two PKC activators. Inhibitors of the AC/cAMP/PKA pathway reversed both the SRIF- and GHRH-induced effects on GH release. Moreover, the GH release evoked by forskolin and 8-Br-cAMP were completely abolished by SRIF. The blockade of the NOS/NO pathway attenuated the GHRH-induced GH release but had minimal effects on the inhibitory actions of SRIF. In addition, inhibitors of the sGC/cGMP pathway did not modify the SRIF- or GHRH-induced regulation of GH release. Taken together, these findings indicate that the SRIF-induced inhibition of GH release is mediated by both the PLC/IP/PKC and the AC/cAMP/PKA pathways and not by the NOS/NO/sGC/cGMP pathway. In contrast, the GHRH-induced stimulation of GH secretion is mediated by both the AC/cAMP/PKA and the NOS/NO pathways and is independent of the sGC/cGMP pathway and the PLC/IP/PKC system.
Keywords
U73122GHRHGH releaseGPCRGH-releasing hormonePLCdiC8PKCSSTRSGCPACAPH891,2-dioctanoyl-sn-glycerolGF109203XSRIFGHRH receptorS-nitroso-N-acetylpenicillamineGnRHPhorbol 12-myristate-13-acetateFBSPBSNOSpKacGMPtPABSAcAMPG-protein-coupled receptorguanosine 3′,5′-cyclic monophosphateinositol phosphatel-NAMEMAPKadenosine 3′,5′-cyclic monophosphateadenylate cyclasebovine serum albuminDopaminediacylglycerolDAGfetal bovine serumSomatostatinSoluble guanylate cyclaseSNAPPhosphate buffered salinephospholipase CSignaling pathwayNitric oxidenitric oxide synthaseGonadotropin-releasing hormoneGrowth hormoneprotein kinase AProtein kinase Cmitogen-activated protein kinasepituitary adenylate cyclase-activating peptideSomatostatin receptor
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Authors
Bin Wang, Chaobin Qin, Cong Zhang, Jirong Jia, Caiyun Sun, Wensheng Li,