Endocrinology, Vol 135, 2214-2219, Copyright © 1994 by Endocrine Society

ARTICLES

Gonadotropin-releasing hormone (GnRH)-receptor coupling to inositol phosphate and prolactin production in GH3 cells stably transfected with rat GnRH receptor complementary deoxyribonucleic acid

JA Janovick and PM Conn
Oregon Regional Primate Research Center, Beaverton 97006.

This study examines the relation between inositol phosphate (IP) production and PRL release in four GGH3 cell lines (GGH(3)1', GGH(3)2', GGH(3)6', and GGH(3)12'; lactotropic GH3 cells that have been stably transfected with rat GnRH receptor complementary DNA). Production of IPs is an early response of GGH3 cells to a GnRH agonist, measurable at 15-30 min and maximal at 60 min after treatment with Buserelin in [3H]inositol preloaded cells. In contrast, PRL release, which requires protein synthesis, is not measurable until 1-3 h and total cAMP production is not measurable until about 24 h (3). In one of the lines studied (GGH(3)2'), PRL was also released in response to TRH. Measurable expression of the PRL gene requires 1-2 days (2). All four lines produced IPs robustly after treatment with Buserelin, although the IP response to TRH is minimal in all lines, being the best in the GGH(3)2' line. Pretreatment of cells with cholera toxin (CTX) or pertussis toxin (PTX) attenuated TRH-induced IP production in GGH(3)1', GGH(3)2', or GGH(3)12' cells. No effect of CTX or PTX is measurable in GGH(3)6' cells in terms of TRH stimulation of IP production. In contrast, both toxins augment Buserelin-stimulated IP production in GGH(3)1' and GGH(3)6' cells, but have no action in the other two lines. Both CTX and PTX inhibit Buserelin-stimulated PRL production. This study suggests that IP production is the earliest measurable response of GGH3 cells to a GnRH agonist, although this event does not appear to be coupled to Buserelin-stimulated PRL release. Further, the studies with toxins suggest that Buserelin and TRH appear to regulate IP production by different mechanisms.

This article has been cited by other articles:

				C. P. Ford, K. V. Wong, V. B. Lu, E. Posse de Chaves, and P. A. Smith Differential Neurotrophic Regulation of Sodium and Calcium Channels in an Adult Sympathetic Neuron J Neurophysiol, March 1, 2008; 99(3): 1319 - 1332. [Abstract] [Full Text] [PDF]

				F. Liu, I. Usui, L. G. Evans, D. A. Austin, P. L. Mellon, J. M. Olefsky, and N. J. G. Webster Involvement of Both Gq/11 and Gs Proteins in Gonadotropin-releasing Hormone Receptor-mediated Signaling in Lbeta T2 Cells J. Biol. Chem., August 23, 2002; 277(35): 32099 - 32108. [Abstract] [Full Text] [PDF]

				G. Maya-Nunez and P. Michael Conn Cyclic Adenosine 3',5'-Monophosphate (cAMP) and cAMP Responsive Element-Binding Protein Are Involved in the Transcriptional Regulation of Gonadotropin-Releasing Hormone (GnRH) Receptor by GnRH and Mitogen-Activated Protein Kinase Signal Transduction Pathway in GGH3 Cells Biol Reprod, August 1, 2001; 65(2): 561 - 567. [Abstract] [Full Text] [PDF]

				S. K. Kang, C.-J. Tai, P. S. Nathwani, and P. C. K. Leung Differential Regulation of Two Forms of Gonadotropin-Releasing Hormone Messenger Ribonucleic Acid in Human Granulosa-Luteal Cells Endocrinology, January 1, 2001; 142(1): 182 - 192. [Abstract] [Full Text] [PDF]

				F. E. M. Rebers, P. T. Bosma, W. van Dijk, H. J. T. Goos, and R. W. Schulz GnRH stimulates LH release directly via inositol phosphate and indirectly via cAMP in African catfish Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2000; 278(6): R1572 - R1578. [Abstract] [Full Text] [PDF]

				G. Maya-Núñez and P. M. Conn Transcriptional Regulation of the Gonadotropin-Releasing Hormone Receptor Gene Is Mediated in Part by a Putative Repressor Element and by the Cyclic Adenosine 3',5'-Monophosphate Response Element Endocrinology, August 1, 1999; 140(8): 3452 - 3458. [Abstract] [Full Text]

				X. Lin and P. M. Conn Transcriptional Activation of Gonadotropin-Releasing Hormone (GnRH) Receptor Gene by GnRH: Involvement of Multiple Signal Transduction Pathways Endocrinology, January 1, 1999; 140(1): 358 - 364. [Abstract] [Full Text]

				X. Lin, J. A. Janovick, and P. M. Conn Mutations at the Consensus Phosphorylation Sites in the Third Intracellular Loop of the Rat Gonadotropin-Releasing Hormone Receptor: Effects on Receptor Ligand Binding and Signal Transduction Biol Reprod, December 1, 1998; 59(6): 1470 - 1476. [Abstract] [Full Text]

				X. Lin and P. M. Conn Transcriptional Activation of Gonadotropin-Releasing Hormone (GnRH) Receptor Gene by GnRH and Cyclic Adenosine Monophosphate Endocrinology, September 1, 1998; 139(9): 3896 - 3902. [Abstract] [Full Text] [PDF]

				D. Stanislaus, S. Ponder, T. H. Ji, and P. M. Conn Gonadotropin-Releasing Hormone Receptor Couples to Multiple G Proteins in Rat Gonadotrophs and in GGH3 Cells: Evidence from Palmitoylation and Overexpression of G proteins Biol Reprod, July 1, 1998; 59(3): 579 - 586. [Abstract] [Full Text]

				A. Ulloa-Aguirre, D. Stanislaus, V. Arora, J. Vaananen, S. Brothers, J. A. Janovick, and P. M. Conn The Third Intracellular Loop of the Rat Gonadotropin-Releasing Hormone Receptor Couples the Receptor to Gs- and Gq/11-Mediated Signal Transduction Pathways: Evidence from Loop Fragment Transfection in GGH3 Cells Endocrinology, May 1, 1998; 139(5): 2472 - 2478. [Abstract] [Full Text] [PDF]

				X. Lin, J. A. Janovick, S. Brothers, M. Blömenrohr, J. Bogerd, and P. M. Conn Addition of Catfish Gonadotropin-Releasing Hormone (GnRH) Receptor Intracellular Carboxyl-Terminal Tail to Rat GnRH Receptor Alters Receptor Expression and Regulation Mol. Endocrinol., February 1, 1998; 12(2): 161 - 171. [Abstract] [Full Text]

				D. Stanislaus, J. A. Janovick, S. Brothers, and P. M. Conn Regulation of Gq/11{{alpha}} by the Gonadotropin-Releasing Hormone Receptor Mol. Endocrinol., June 1, 1997; 11(6): 738 - 746. [Abstract] [Full Text]

				U. B. Kaiser, P. M. Conn, and W. W. Chin Studies of Gonadotropin-Releasing Hormone (GnRH) Action Using GnRH Receptor-Expressing Pituitary Cell Lines Endocr. Rev., February 1, 1997; 18(1): 46 - 70. [Abstract] [Full Text]