Rate of Cumulus Cell Apoptosis from Fertilized and Unfertilized Oocytes and Acid Phosphatase Levels in Follicular Fluids after Intracytopasmic Sperm Injection

The main role of cumulus cells (CC) is to provide nutritious materials for developing oocytes. Follicular fluid (FF) contains the enzyme acid phosphatase, which plays a role in ovulation and fertilization of oocyte. The objective of this prospective study was to evaluate the levels of acid phosphatase in FF and the rate of apoptosis in CC of fertilized and unfertilized oocytes in intracytoplasmic sperm injection (ICSI) program with male factor infertility. Following ovarian hyperstimulation, 101 mature oocytes were prepared for ICSI. Fertilized (n = 51) and unfertilized (n = 50) oocytes were evaluated for apoptosis in CC. CC of each oocyte were stained with Hoechst 33258 for immunofluorescent microscopy. For evaluation of acid phosphatase, FF was centrifuged and the enzymes levels were measured with spectrophotometer. Nuclei of apoptotic cells were fragmented, the chromatins condensed, and the apoptotic bodies were observed in some cells. Rates of apoptotic CC in fertilized and unfertilized oocytes were 15.83% and 13.34%, respectively (P>0.05), r = 0.520). The acid phosphatase level was reduced as the rate of apoptosis increased P<0.05, r = -0.520). Also, the concentration of the enzyme increased when the percentage of normal CC increased P<0.05. Our results confirm that neither the evaluation of CC apoptosis, nor the level of acid phosphatase have a prognostic value in the outcome of ICSI. However, the FF level of acid phosphatase is directly related to the quality of retrieved MII oocyte..