Studies On Granulosa Cell Apoptosis And Its Influencing Factors In The Pig

Generally, there are many follicles undergoing atresia in mammalian ovary; but the mechanism of follicle atresia is still unclear. Recently with the development of studies on apoptosis, it has been realized that granulosa cell apoptosis might be the cause of follicle atresia. In order to further study the mechanisms of follicle atresia and factors affecting granulosea cell apoptosis, we conducted this study using pigs as experimental material. The contents of this study can be summarized as follws: 1. Selection of methods for detecting apoptotic granulosa cells. 2. The rate of apoptotic granulosa cells at different stages of oestrous cycle. 3. Effects of PMSG on follicle development and granulosa cell apoptosis in the sows. 4. Effects of PMSG on follicle development and granulosa cell apoptosis in the immature gilts. 5. The effects of PMSG on apoptosis of granulosa cells cultured in vitro. 6. The effects of IGF-l on apoptosis of granulosa cells cultured in vitro. The results are as follows:I.There were many granulosa cells undergoing apoptosis in the atretic follicles in the pig.2.There was a significantly positive correlation between the rate of apoptotic granulosa cells detected by the H.E staining and that through TU7NEL. Under the conditions in our study, TUNEL can be replaced by granulosa cells smear H.E staining to detect apoptosis in granulose cells.3.Detected by H.E staining and TUNEL, the rate of apoptotic granulosa cells of the atretic follicle was 34% and 39.2% respectively, while that of the healthy follicle was 3.6% and 9%, respectively.4.There was a significant difference among the rates of apoptotic granulosa cells in follicles with different diameters at different stages of the oestrous cycle, and the rate in large follicles was low and did not change in a big margin at different stage of the oestrous cycle. The rate in small follicles was high and changed a great deal at different stage of the oestrous cycle.5.The granulosa cell apoptosis in the small and medium-sized follicles in the sow was significantly suppressed by injection of PMSG, but this effect lasted only for 72 hr.6.The rates of apoptotic granulosa cells in all kinds of follicles in immature gilts were as high as atretic follicles; it decreased significantly after injection of PMSG, but it was higher and lasted shorter than that of mature pig.7.Apoptosis of in vitro cultured granulosa cells was significantly suppressed by PMSG, and the effects varied with concentration.8.Apoptosis of in vitro cultured grartulosa cells was significantly suppressed by IGF-1 and the effect was dependent on concentration.Liu Zhonghua, Animal Histology and EmbryologyAdvisor:Pref. Tan Jinghe...