Frozen storage of the oocytes has been used in a few mammalian species including mouse, hamster, human and cattle. However, frozen4hawed oocvtes show different sperm penetration on the levels of the zona pellucida and the plasma memhrane when compared with fresh oocytes. To elucidate biological changes occurring during freezing and thawing, we examined the kinetics of sperm penetration into frozen-thawed hamster oocytes. Oocytes obtained from superovulated female golden hamsters were frozen-thawed in an autofreezer according to an established method. Fresh and frozen4hawed oocytes were fertilized in vitro with capacitated hamster spermatozoa after removing the zona pellucida. The oocytes were examined at 1, 2, 3 and 6 h postinsemination. Sperm penetration found to be 1 h delayed in frozen-thawed oocytes. Other parameters such as degree of polyspermy and decondensing sperm heads were not affected by freezing and thawing. The results suggest that freezing and thawing may cause changes in the egg membrane surface and subsequently which leads to delay in the sperm-egg fusion.

Ethane 1,2-dimethane sulfonate(EDS)은 Leydig cells(LC)만을 선별적 사멸을 유도하는 약물로서 가역적인 테스토스테론(testosterone, T) 결핍 흰쥐 모델을 만드는데 널리 사용된다. 본 연구에서는 수컷 흰쥐 뇌하수체의 생식소자극호르몬인 LH와 FSH의 발현에 미치는 EDS 투여 효과를 조사하였다. 성숙한 수컷 흰쥐(SD strain, B.W.)에 EDS(75 mg/kg, i.p.)를 1회 복강주사하고 주사 후