Effect Of MDA,SOD Levels And Incidence Of Apoptosis In Granulosa Cells On Oocyte Quality And The Outcome Of IVF-ET

OBJECTIVE: The aim was to determine the effects of oxidative stress and apoptosis on the quality of oocytes,embryos and the outcome of IVF-ET.MATERIALS AND METHODS: The study was carried out between Augest and October 2007 at the Reproductive Center of Xiang Ya hospital. We enrolled 51 normally cycling women undergoing an IVF-ET programme for tubal factor infertility; the women with endometriosis or endocrine diseases and those with male factor infertility were excluded. All women were in their first IVF cycle. All 51 patients underwent a long GnRH agonist protocol for pituitary downregulation followed by controlled ovarian hyperstimulation with rFSH. Granulosa cells were isolated from all aspirated follicular fluid using gradient centrifugation. Levels of malondialdehyde (MDA) and malondialdehyde (SOD) were measured by the thiobarbituric acid (TBA) and the chemiluminescence method , respectively. The apoptosis was studied by flow cytometry using propidium iodide. All objects were classified to pregnant and non-pregnant group based on the outcome of IVF-ET. Compare MDA, SOD levels and incidence of apoptosis of granulosa cells between pregnant and non-pregnant group, and examine the correlation among the three parameters and the number of retrieved oocytes, mature oocytes, fertilization, cleavage, and good-embryo rates.RESULTS:1,The clinical pregnancy rate was 50.98%. The mean MDA level was 1.414 nmol /gprot, the mean SOD level was 3.94×10~3NU/gprot, and the mean incidence of apoptosis was 21.88%. 2,Pregnant patients showed significantly lower MDA level (1.1±0.56vs.1.7±0.72;P<0.05),the incidence of apoptosis (19.0±5.59% vs.24.8±6.57%; P<0.05) and higher SOD level (4.4±0.99 vs. 3.5±1.08; P<0.05) in granulose cells and good-embryo rate (68.44% vs. 52.74%; P<0.05) compared with non-pregnant patients.3,A negative correlation was seen between fertilization rates and MDA(r=-0.43; p = 0.002). No correlation was seen among MDA level and the number of retrieved oocytes, oocyte maturity, cleavage and good-embryo rate. No correlation was seen among SOD level and the number of retrieved oocytes, mature oocytes, fertilization rate, cleavage rate, and good-embryo rate. A negative correlation was seen between the incidence of apoptosis and the number of retrieved oocytes(r =-0.286; p = 0.042), mature oocytes(r=-0.33; p=0.020) and good-embryo rate(r= -0.311; p=0.026).4,There was negative correlation between MDA and SOD levels(r = -0.471; p< 0.001); positive correlation between MDA level and incidence of apoptosis(r=0.475; p<0.001).CONCLUSION:1,These results indicate that oxidative stress may induce apoptosis in granulose cells and subsequently lower oocyte quality and led to poor outcome of IVF-ET.2,The incidence of apoptosis of granulose cells could be used as a indicator of developmental ability of the oocyte and success of IVF-ET.