Homologous Up-Regulation of the Gonadotropin-Releasing Hormone Receptor inalphaT3-1 Cells Is Associated with Unchanged Receptor Messenger RNA (mRNA) Levels and Altered mRNA Activity

摘要

The role of altered biosynthesis was investigated in the mouse gonadotrope cellline, by studying the homologous up-regulation of GnRH receptor binding, mRNA levels, and mRNA activity. After GnRH exposure, ligand binding was performed on cell membranes. To correlate changes in receptor number and measurements of biosynthetic activity, GnRH receptor mRNA levels were quantitated by solution hybridization/RNase protection assay and Northern blot analysis, and the capacity of RNA from treated cells to direct the synthesis of new receptors (mRNA activity) was evaluated using a Xenopus oocyte-based bioassay. The authors' results show that although the levels of GnRH receptor mRNA do not vary, treated cells with increased binding capacity show a corresponding increase in cellular GnRH receptor mRNA activity in oocytes.