Ovarian follicular fluid peptide (OFFP) purified from sheep ovaries ha
s been earlier shown to induce degeneration of ovarian follicles in mi
ce. In the present study, whether the effect of OFFP on granulosa cell
s was similar to apoptosis was studied using three parameters. Immatur
e mice injected with pregnant mare serum gonadotropin on day 0 were ad
ministered with 10 or 20 mu g of OFFP on day 1 and autopsied on day 2.
The granulosa cells were collected from the ovarian follicles. The pr
esence of apoptotic bodies were observed by staining the cells with ac
ridine orange. DNA profiles of DAPI-stained cells analysed by flow cyt
ometry also revealed apoptotic response to OFFP. Furthermore, agarose
gel electrophoresis of low molecular weight DNA fraction extracted fro
m the cells of OFFP-treated animals confirmed ladder formation and ind
uction of apoptosis and not necrosis in granulosa cells. In conclusion
, all the three parameters indicated apoptotic changes in granulosa ce
lls of ovarian follicles in mice treated with OFFP. The effect of OFFP
seems to be exerted directly on the granulosa cells showing its autoc
rine role in the process of follicular atresia. This is discussed in t
he light of other intra/extra ovarian factors.