ARS | Publication request: ESTROGEN REGULATION OF RAT PITUITARY GONADOTROPIN-RELEASE HORMONE RECEPTOR MRNA LEVELS BY IN SITU AND SLOT BLOT ANALYSIS.

Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 1995
Publication Date: N/A

Technical Abstract: It is well known that the level of pituitary gonadotropin-releasing hormone binding varies during the estrous cycle of the rat. The mechanisms underlying hormonal regulation of the gonadotropin-releasing hormone receptor (GNRH-R) are not known. Kaiser et al. (Endocrinol 133:931) found a non-significant increase in GNRH-R mRNA levels in rat pituitary tissue during 2 days of estrogen (EB)-replacement. Slot blot analysis utilizing riboprobe complementary to rat GNRH-R confirmed this. GNRH-R mRNA only non-significantly increased after 24 and 48 hours of EB treatment of ovariectomized (OVX) rats. Quantitative IN SITU hybridization assays showed a three-fold increase in GNRH-R mRNA levels after 48 hours of EB treatment when compared to OVX rats. No differences after 12 h were observed. GNRH-R mRNA cells showed a clustered distribution in pituitary tissues. This increase in GNRH-R mRNA could be due to enhanced GNRH-R transcription within these clusters of cells. The effects of estrogen on GNRH-R mRNA levels detected in specific brain regions are currently being studied.