Expression of 11 p-Hydroxysteroid Dehydrogenase: DISCUSSION(2)
11pHSD1 has previously been localized by immunocyto-chemistry and in situ hybridization to oocytes and CL, but not granulosa cells or thecal-interstitial cells on the morning of proestrus, i.e., shortly before onset of the LH surge. It was also demonstrated in that study that NAD-dependent 11pHSD activity (i.e., 11pHSD2) is present in the ovary of the proestrous rat. This is consistent with the low level of 11pHSD1 and high level of 11pHSD2 mRNAs detected at an equivalent stage of follicular maturity in eCG-treated ovaries, particularly in isolated granulosa cells. 11pHSD2 mRNA was also localized to the rat CL during late pregnancy, when no signal for 11pHSD1 mRNA was detected. The present data, based on a sensitive ribonuclease protection assay, show that mRNAs encoding both 11(3HSD isoforms, as well as GR and MR, can be detected in CL, indicating the CL as a potential site of both of corticosteroid metabolism and action in the rat. antibiotic levaquin
Our results unequivocally locate all four mRNAs to isolated granulosa cells, where both 11pHSD isoforms and MR, but not GR, are developmentally regulated. Since the isolated granulosa cells would have contained some oocytes, we do not rule out the possibility that 11 (3HSD expression by the oocyte also contributes to these results. Residual ovary (which inevitably contained residual granulosa cells and oocytes) displayed development-related changes in mRNA expression that were qualitatively and quantitatively similar to those shown by isolated granulosa cells, except for 11pHSD1 in group P, where expression of the mRNA was much higher in residual ovary than in granulosa cells.