Effects of androgens on proliferation, viability, and aromatase activity of bovine granulosa cells in vitro

This study determined the effects of dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), 19-hydroxy-androstenedione (19-OH-A) and 19-hydroxy-testosterone (19-OH-T) on proliferation, viability, and aromatase activity of bovine granulosa cells (GCs) from first-wave dominant follicles. In Experiment I, GCs were cultured in media containing various doses of 19-OH-A, 19-OH-T, DHEA, DHT, or no androgen (NA) for 18 h. GC proliferation, viability, and estradiol production were then assessed. Treatment with androgens did not alter GC proliferation. However, viability of GCs was enhanced with 19-OH-A, 19-OH-T, or DHEA compared with NA or DHT treatment. GCs treated with 19-OH-A and 19-OH-T produced more estradiol and at a greater rate than those treated with DHEA. GCs treated with DHT or NA did not produce estradiol. In Experiment II, GCs were pre-treated for 6 h in media containing various amounts of 19-OH-A, 19-OH-T, DHEA, DHT, or NA. GCs were washed and cultured for a 12 h test period in media containing 19-OH-A or NA then aromatase activity was assessed. Pre-treatment with 19-OH-A or 19-OH-T enhanced aromatase activity compared with DHEA, DHT, or NA. In Experiment III, DHT diminished capacity of GCs to convert 19-OH-A to estradiol. In conclusion, type and amount of androgen altered GC viability, estradiol production, and aromatase activity implying that androgens have an important role in regulation of dominant follicle growth and atresia.