Expression of GnRH and GnRH-receptor mRNAs in the Human Placenta / 체질인류학회지

ABSTRACT

Placental GnRH is one of the potential paracrine regulator of hCG secretion from the trophoblasts during pregnancy. However, this paracrine function is not clearly confirmed. The present study was designed to evaluate the possible correlation between the synthesis and cellular distribution of GnRH and GnRH -receptor in the placental villi. 6 to 40 weeks termed twenty five human placental tissues were used in this study. GnRH and GnRH -receptor mRNAs were localized in the placenta by in situ hybridization using the corresponding cRNA probes. GnRH mRNA was present in all cell types of placenta including cytotrophoblasts, syncytiotrophoblasts and stromal cells. The GnRH -receptor mRNA signals were localized in both cytotrophoblasts and syncytiotrophoblasts. The GnRH -receptor mRNA signals were also localized in some stromal cells at the full term placenta. GnRH mRNA signals were detected abundantly at 6 ~7 weeks and the intensities were remarkably increased with the following gestational ages. GnRH -receptor mRNA signals were detected at 6 ~7 weeks, peaked at 9 ~10 weeks, declined at 23 ~24 weeks and focally expressed at full term placenta. The present study demonstrates that GnRH mRNA is expressed in all cell types of the placenta, however GnRH -receptor mRNA is expressed only in the cytoptrophblasts and syncytiotrophoblasts and exhibits parallel change with the time course of hCG secretion during pregnancy. These data provide a morphological understanding that placental GnRH has a paracrine/autocrine role through its receptor from 6 ~7 weeks gestation to term placenta.