[Experimental study of c-erbB2 on the fertilization in mouse].

Aim and Methods:The distribution of ErbB 2 in mouse testis, epididymidis, ovaries, oocyte cumulus cells complexes in oviducts and sperms was investigated immunohistochemically. To study the effect of c erbB 2 on mouse fertilization in vitro , various concentrations of c erbB 2 antisense oligonucleotides (c erbB 2 ASODNs) were incubated with sperms and oocyte cumulus cells complexes during fertilization in vitro . To explore possible mechanisms involved in fertilization, the relationship between c erbB 2 ASODNs and GABA,or dbcAMP,or verapamil during fertilization in vitro was also observed. Results: ErbB 2 oncoprotein was observed in epithelial cells in epididymis, sperms and cumulus cells. C erbB 2 ASODNs inhibited the rate of fertilization in vitro in a dose dependant way. The fertilization rate of the control group, low(5 μmol/L), medium(10 μmol/L),high(20 μmol/L) concentration c erbB 2 ASODNs group, and nonsense at oligonucleotides group (20 μmol/L) was 38.3%, 19.6%, 10.7%, 5.0%, and 33.8% respectively. Integral optical density immustaining of ErbB 2 in sperms was notably reduced. Medium and high concentration of c erbB 2 ASODNs notably inhibited cumulus cells adhering to inner wall of Petri dish.Treated alone with GABA or dbcAMP, the rate of fertilization was increased. Both GABA and dbcAMP partially inversed the ASODNs inhibition effect on fertilization rate, but neither of them showed significant effect on sperm integral optical density of ErbB 2 immustaining. In contrast, verapamil inhibited fertilization rate. Co treated with c erbB 2 ASODN, verapamil showed synergic inhibiting effect on fertilization with c erbB 2 ASODN. Verapamil also inhibited the expression of c erbB 2 in sperms. Conclusion:It is suggested that c erbB 2 is closely correlated with fertilization. Ca 2+ may inhibit fertilization in vitro through regulation the expression of c erbB 2 gene in sperm cells, while both of GABA and dbcAMP may affect the process of fertilization through the way other than c erbB 2 expression in sperm cells.