DURATION EFFECT FROM HUMAN CHORIONIC GONADOTROPHIN (hCG) INJECTION TO OOCYTE RETRIEVAL ON INTRACYTOPLASMIC SPERM INJECTION (ICSI) PERFORMANCE IN MICE

Abstract

This study was conducted to compare the effect of duration from human chorionic gonadotrophin (hCG) injection to oocyte retrieval (13-15 h or 16-18 h) on intracytoplasmic sperm injection (ICSI) performance in mice. The mice were superovulated with 5 IU of pregnant mare’s serum gonadotrophin (PMSG) and subsequently 5 IU of hCG 48 h later via intraperitoneal (i.p.) injection. The oocytes were retrieved 13-15 h or 16-18 h after hCG administration. The number of ovulated oocytes showing the first polar body (PB1; metaphase II indicating matured oocytes) were higher at 13- 15 h compared to 16-18 h post-hCG injection (P < 0.05). Only oocytes with the PB1 were used for ICSI. All cleavage rates following ICSI were shown to be higher in oocytes retrieved at 13-15 h post-hCG compared to 16-18 h post-hCG injection (P < 0.05). In conclusion, it is suggested that oocytes can be retrieved at 13-15 h post-hCG injection and longer duration may be detrimental for ICSI performance in mice. ABSTRAK Kajian ini telah dijalankan untuk membandingkan kesan tempoh suntikan dari human chorionic gonadotrophin (pos-hCG) ke perolehan oosit (13-15 jam atau 16-18 jam) ke atas prestasi suntikan sperma intrasitoplasma (ICSI) dalam mencit. Mencit telah disuperovulasi dengan 5 IU pregnant mare’s serum gonadotrophin (PMSG) dan kemudian dengan 5 IU hCG jarak 48 jam secara suntikan intraperitoneum (i.p.). Oosit dipungut 13-15 jam atau 16-18 jam selepas sunitkan hCG. Bilangan oosit terovulasi diperolehi yang menunjukkan jasad kutub pertama (PB; metafasa II menunjukkan oosit matang) adalah lebih tinggi pada tempoh 13-15 jam berbanding dengan 16-18 jam suntikan pos-hCG (P<0.05). Hanya oosit dengan PB1 digunakan untuk ICSI. Semua kadar pembelahan selepas ICSI telah ditunjukkan lebih tinggi pada tempoh 13-15 jam berbanding dengan suntikan 16-18 jam pos-hCG (P<0.05). Kesimpulannnya, adalah dicadangkan bahawa oosit boleh dipungut pada tempoh suntikan 13-15 jam pos-hCG dan tempoh yang lebih panjang mungkin memnjejaskan prestasi ICSI dalam mencit. (Keywords: Post-hCG, Oocyte post-maturity, Intracytoplsmic sperm injection, Mice)