Endocrinology, Vol 133, 2617-2623, Copyright © 1993 by Endocrine Society

ARTICLES

In situ demonstration and characterization of progonadotropin-releasing hormone messenger ribonucleic acid in first trimester human placentas

TM Duello, SJ Tsai and PJ Van Ess
Department of Obstetrics and Gynecology, University of Wisconsin School of Medicine, Madison 53706.

GnRH has been shown to play a role in the regulation of secretion of hCG by human placenta. Immunocytochemical studies have demonstrated the presence of the peptide, but do not address whether the GnRH is maternal, fetal, or placental in origin. In situ hybridization studies using a biotinylated pro-GnRH cDNA were, therefore, undertaken to determine the distribution of pro-GnRH mRNA in first trimester placental samples. Using an avidin-biotin-Cy.5 detection system in conjunction with laser scanning confocal microscopy, pro-GnRH mRNA was shown to be present in both the cytotrophoblast and syncytiotrophoblast cells of placental villi, although not in the cells of the fetal connective tissue. Prior hybridization with a 200-fold excess of unlabeled probe blocked hybridization of the labeled pro-GnRH probe. Southern and sequence analysis demonstrated that the probe hybridized to a transcript identical to hypothalamic GnRH. Immunocytochemical staining using an antiserum to amino acids 6-16 of pro-GnRH demonstrated the presence of translated pro-GnRH in both the cytotrophoblast and syncytiotrophoblast epithelia. We conclude that the synthesis of pro-GnRH by both the cytotrophoblast and the syncytiotrophoblast of human placenta is consistent with either an autocrine or a paracrine mode of GnRH regulation of hCG secretion.

This article has been cited by other articles:

				C.-S. Chou, A. G. Beristain, C. D. MacCalman, and P. C. K. Leung Cellular Localization of Gonadotropin-Releasing Hormone (GnRH) I and GnRH II in First-Trimester Human Placenta and Decidua J. Clin. Endocrinol. Metab., March 1, 2004; 89(3): 1459 - 1466. [Abstract] [Full Text] [PDF]

				T.A. Bramley, K. Campbell, and G.S. Menzies Human placental GnRH-like factors: II. Inhibition of enzymatic degradation of GnRH-II and [D-Trp6]GnRH ethylamide tracers by human term placental cytosol fractions reveals the presence of GnRH-binding protein(s) Mol. Hum. Reprod., May 1, 2003; 9(5): 291 - 300. [Abstract] [Full Text] [PDF]

				T. M. Siler-Khodr and M. Grayson Salmon GnRH and Its Analogues Bind the Human Placental Receptor Reproductive Sciences, July 1, 2001; 8(4): 233 - 238. [Abstract] [PDF]

				S. Rama and A.J. Rao Embryo implantation and GnRH antagonists: The search for the human placental GnRH receptor Hum. Reprod., February 1, 2001; 16(2): 201 - 205. [Abstract] [Full Text] [PDF]

				T.A. Bramley and G.S. Menzies Human placental gonadotrophin-releasing hormone-like factors: an artefact of human placental peptidases? Mol. Hum. Reprod., February 1, 2000; 6(2): 113 - 126. [Abstract] [Full Text] [PDF]

				T.A. Bramley, H.P. Boyle, and G.S. Menzies Human placental GnRH-like factors: parallel displacement in GnRH immuno- and receptor-binding assays can be caused by degradation of radiolabelled GnRH tracers Mol. Hum. Reprod., December 1, 1999; 5(12): 1095 - 1106. [Abstract] [Full Text] [PDF]