Differential steroidogenic response of granulosa cells from different regions within a bovine follicle to FSH stimulation in vitro

Abstract

The objectiv of the present study was to investigate the steroidogenic capacity of granulosa cells from different areas within a bovine follicle. Bovine granulosa cells were isolated by gently scraping the inner layer of 5 to 8 mm diameter follicles (mostly mural granulosa cells) or aspirated from follicles using a 10 ml syringe and neddle (mostly antral and cumulus granulosa cells). Scraped and aspirated granulosa cells (2-3 x 10(5) viable cells/well) were cultured with either basal medium (control) or 10 mu mu FSH for 4 days at 37 degrees C in a humidified atmosphere in 1 ml of serum-free culture medium. Aspirated granulose cells produced (P < 0.001) 10 to 20 times more progesterone (for control, 25.0 +/- 3.1 and for 10 mu mu FSH, 55.4 +/- 6.8 ng progesterone/mu g DNA) than scaped cells (for control, 0.9 +/- 0.2 and for 10 mu m FSH, 5.4 +/- 0.6 ng progesterone/mu g DNA). These results suggest that mural granulosa cells are less differentiated than antral and/or cumulus cells.