C-erbB <sub> 2 </ Sub> With Mouse THEFERTILIZATION, Research

Aims and methods: To investigate the distribution of oncoprotiem, ErbB2 in mouse testis, epididymidis, ovaries, oviducts, oocytes-cumulus cells complex and sperms, immunobistochemical method was used. To study the effect of c-erbB2 on mouse fertilization in vitro, varied concentration of c-erbB2 ASODNs was incubated with sperms and oocytes during fertilization in vitro. To explore the possible mechanism involved in the fertilization, the relationship of y -GABA, dbcAMP, Verapamil between c-erbB2 anlisenseoligonucleotides (c-crbB2 ASODNs) during the fertilization in vitro was also observed. Results: 1. ErbB2 oncoprotein was found on the luminal surface of the epithcial cells in the epididymis and on the plasma membrane of cumulus cells and sperms. 2. c-erbB2 ASODNs inhibited the rate of fertilization in vitro by a dose-dependant way. The fertilization rate of the control group, low(5 ii molIL), medium(10 i~?moLt), bigh(20 Li molIL) concentration c-erbB2 ASODNs group, and nonsensc(20 i~ molIL) oligonucleotides tat group were 38.3,19.6,10.7,5.0 and 33.8%, respectively. ErbB2 駇nunohistochemistry stain integral optical density was also reduced. Medium and high concentration c-erbB2 ASODNs also inhibited cumulus cells adhering to inner wail of Petri dish. 3. Treated alone withy-GABA and dbcAMP, the rate of fertilization was increased. Co-treated with c-erbB2 ASODNs, both of Y -GABA and dbcAMP partially inversed the ASODNs inhibition effect on fertilization rate, but both show no significant effect on sperm ErbB2 immunohistochemistiy stain integral optical density. By contrast, Verapamil inhibited the fertilization rate. Co-treated with c-erbB2 ASODNs, Verapamil showed synergic inhibiting effect on the fertilization with c-erbB2 ASODNs. Verapamil also inhibited the expression of c-erbB2 in sperm plasma membrane. Conclusion: It is suggested that c-erbB2 is involved in the fertilization process. The inhibit effect of Verapamil on the fertilization rate in vitro may mediated by the expression of c-erbB2 gene in sperm cell. Both of i?-GABA and dbcAMP promoted the fertilization rate in vitro, but other than the pass way of expression of c-crbB2 gene in sperm cell, alternative pass way may occurred.