Superovulation of mice with pituitary and extrapituitary gonadotropins

The possibility of manipulating mammalian eggs in vitro represents a technological basis of experimental change of the reproduction process, and can result in the creation of new, more suitable genotypes. It is necessary to get a sufficient number of oocytes and/or embryos to extend the transfer of embryos and to develop the micromanipulation techniques. Therefore the effect of superovulation in donors of embryos is used. Stimulation of ovaries with gonadotropic hormones is a commonly used method of superovulatory treatment. Adult females of outbred mice species SPF-ICR (white mouse) were used as donors of embryos at the age of one month, weight 20-25 g, in the experiment. Superovulation in mice was stimulated by intramuscular application of 10 i.u. PMSG (Serum gonadotropin, Bioveta Ivanovice na Hane) combined with 10 i.u. HCG. Three hormonal preparations were tested in the HCG function: Praedyn-chorium gonadotropin, Leciva Praha; Dirigestran-synthetic hypothalamic hormone, gonadorelin, Leciva Praha; Receptel-synthetic hypothalamic hormone, buserelin, monopeptide analogue, Hoechst AG FRG. After the hormonal stimulation of 116 mice 1420 ova were gained, out of which 871 (61.38 %) were fertilized. The lowest number of ova was gained after the combination of hormones PMSG and Praedyn (Table I). With the application of Dirigestran in the function of HCG 1.32 times more ova were gained, and with application of Receptal 1.71 times more compared with the application of Praedyn. The statistical evaluation by chi** (2) test showed that the combination of hormones PMSG and Receptal is significantly more effective in the process of superovulation response induction compared with the combination PMSG and Praedyn. The comparison of the superovulatory effect of Dirigestran and Receptal application in the function of HCG did not confirm the significant difference in the total number of recovered embryos, or in the number of fertilized ova. The results of this study show that the LH-RH component (Dirigestran) and mainly the component LH-FSH (Receptal) favourably influence the production of superovulatory effect in mice. Therefore it would be feasible to use the given preparations in combination with PSMG to stimulate superovulation in mice.