EffECT Of 3-IsObUTyl-1-mEThyl-xaNThINE ON RabbIT sUpEROvUlaTION aND Egg RECOvERy

The aim of our study was to examine the influence of 3-isobutyl-1-methyl-xanthine (IBMX), inhibitor of cAMP and cGMP phosphodiesterases on the reproductive efficiency of gonadotropin-stimulated rabbits. Ovarian cycle and ovulation of control rabbits were induced by PMSG followed by hCG administration. Experimental animals received PMSG and hCG together with IBMX (at dose 5 or 25 mg/animal). After ovulation and mating, the animals were killed; the pronuclear stage eggs were flushed from the oviducts and cultured up to blastocyst stage. Numbers of ovarian corpora lutea, ovulated oocytes and oocyte-derived embryos reaching blastocyst stage were determined. It was observed, that in�ections of IBMX at dose of 5 mg/animal significantly increased all these parameters. IBMX, when in�ected at dose of 25 mg/ml, increased only the number of developed embryos, but not the number of ovulations and ovulated oocytes. These data demonstrate that IBMX can enhance the stimulatory effect of gonadotropins on the rabbit ovulation, oocyte maturation, and embryo yield.