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 (2-3×105 viable cells/ well) were cultured with either basal medium (control) or 10 μμ FSH for 4 days at 37°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 μμ FSH, 55.4±6.8 ng progesterone/μg DNA) than scaped cells (for control, 0.9±0.2 and for 10 μm FSH, 5.4±0.6 ng progesterone/μg DNA). These results suggest that mural granulosa cells are less differentiated than antral and/or cumulus cells.