Inhibitory effect of follicular fluid on RNA synthesis of rat granulosa cells in vitro

Abstract

Follicular fluid was collected at the slaughterhouse from cow follicles. The levels of RNA synthesis by cells incubated in control medium varied in different experiments, perhaps because of metabolic differences in granulosa cell samples. There was a significant reduction in radioactivity [3H-uridine] of TCA [trichloroacetic acid] insoluble fraction [an estimate of free uridine] when granulosa cells where cultured in the presence of follicular fluid. RNA synthesis was decreased by up to 30%. There was no significant difference between effects of total and estrogen-free follicular fluid. The inhibition does not seem to be due to a cytotoxic effect of follicular fluid because cells exhibited the same degree of viability, as judged by trypan-blue staining test, whatever the type of incubation. The radioactivity of the TCA-insoluble fraction and levels of RNA synthesis were not affected by the concentration of luteinizing hormone in the medium.