BACKGROUND Shortly after stimulation by the preovulatory surge of luteinizing hormone (LH), oocytes arrested at the late prophase I resume meiosis characterized by germinal vesicle breakdown (GVBD), chromosome condensation, and extrusion of the first polar body in preparation for fertilization and early embryonic development. However, oocytes express few or no LH receptors and are insensitive t...

Rabbit oocytes from preovulatory follicles resume meiosis up to metaphase II in normal delay when cultured in TC 199 supplemented with rabbit and calf sera and chick embryo extract. They are fertilizable, but such oocytes are unable to assume transformation of the sperm head into a normal nucleus, the male pronucleus. Rabbit preovulatory follicle can be maintained in healthy conditions for at l...

Although there are many reports on the effect of glucose metabolism on oocyte nuclear maturation, there are few studies on its effect on ooplasmic maturation. By manipulating glucose metabolism pathways using a maturation medium that could support oocyte nuclear maturation but only a limited blastocyst formation without glucose, this study determined effects of glucose metabolism pathways on oo...

The addition of alpha-amanitin to extrafollicular, cumulus-enclosed ovine oocytes at explantation inhibits meiotic maturation and prevents many of the changes in protein synthesis that normally accompany maturation. By contrast, these inhibitory effects are considerably reduced by either delaying the addition of the drug for 1-4 h or by denuding the oocytes of all associated cumulus cells at th...

This study was designed to clarify bilaterally effect of long-time varicocele on left and right testes and to identify the effect of varicocele on maturation divisions during spermatogenesis. Moreover, the percentage of seminiferous tubules (STs) with I-VIII and IX-XIV stages of spermatogenesis and sperm parameters such as sperm motility and abnormality types were evaluated. The left varicocele...