Effect of estradiol on relative gene expression of estrogenic and progestagenic enzymes in Holstein cow granulosa cells in vitro

The objective of this study was to determine the effect of estradiol on mRNA levels encoding FSH receptor (FSHR)، LH receptor (LHR)، estrogenic and progestagenic enzymes. Briefly، follicles between 2 and 5 mm diameter were dissected from the ovaries of adult cows collected from a local abattoir، cells were collected by rinsing the follicle walls with Dulbecco Modified Eagle medium/F12 (DMEM/F12). A viable cell count was performed in the presence of 0. 4 % Trypan Blue and were cultured in 24-well plates for 6 days. Treatments were 1) 500،000 cell/500 ml، 2) 500،000 cell/200 ml، 3) 500،000 cell/500 ml and estradiol 4) 500،000 cell/ 200 ml and estradiol. To measure steroid secretion، the medium was removed for steroid assay on day 6 and measured by RIA. To measure mRNA abundance، cells were collected into Trizol and stored at −80 °C until RNA extraction. All data were analyzed by JMP (SAS). Results showed that addition of estradiol to granulosa cell culture medium was stimulated the E2 synthesis in granulosa cells by increasing key enzymes involved in the conversion of androgens to E2 (estrogenic enzyme) and also inhibited the progestin synthetic pathway by decreasing mRNA level of progestagenic enzyme involved in the conversion of cholesterol to P4 and finally decreasing luteinization and improve follicle healthy or oocyte developmental competence.