Abstract: 236

EXPRESSION OF P450 SIDE-CHAIN CLEAVAGE AND P450 17-HYDROXYLASE MESSAGE AND PROTEIN IN THE PRE AND POSTNATAL HAMSTER OVARY.

James R. Schwartz^{1 *}, Shayamal K. Roy^{1 *}
Olsen Center for Women’s Health, Departments of OB/GYN and Physiology and Biophysics, University of Nebraska Medical Center, Omaha, NE 68198-4515. ¹

Although thecal cells appear to originate from interstitial cells, the mechanisms of thecal cell differentiation are unclear. To better understand these mechanisms, ovaries from days 12-15 of gestation and from 1-20 days postnatal were analyzed for CYP SCC and CYP17 protein and mRNA expression. CYPSCC immunoactivity appeared in interstitial cells for the first time on day 13 postnatal and the intensity increased significantly in thecal and interstitial cells with further ovarian development. On the contrary, faint CYP17 immunostaining was noted by day 13 postnatal in few interstitial cells adjacent to follicles with 5-6 layers of granulosa cells. CYP17 immunoreactivity in developing thecal cells increased noticeably by day 17 and distinct theca-specific immunofluorescence was evident by days 18-20 of postnatal life. CYP17 mRNA expression however, was first noted at postnatal days 1 and 2 but the expression disappeared by day 3 and remained undetectable until day 10 of age. Distinct expression of both CYPSCC and CYP17 mRNA occurred by day 11 postnatal and continued thereafter. These results correlate with the rise in plasma LH in the neonatal hamster, and suggest that the differentiation of interstitial cells may be associated with their ability to respond to LH as multilayered preantral follicles develop.

    This abstract is being presented on Monday, August 2 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.