Submitted January 26, 2004
Returned for revision February 23, 2004
Accepted March 4, 2004
Reproductive Technology
A New Alternative Method for Superovulation Using Passive Immunization Against Inhibin in Adult Rats
Harumichi Ishigame ,
Mohamed S. Medan ,
Gen Watanabe ,
Zhanguan Shi ,
Hisahi Kishi ,
Koji Y. Arai ,
and
Kazuyoshi Taya *
* To whom correspondence should be addressed. E-mail: taya{at}cc.tuat.ac.jp.
Abstract
The present study was undertaken to investigate the effects of passive immunoneutralization of endogenous inhibin on ovulation rate and embryo development in vivo and in vitro in order to establish a new alternative superovulation method in the adult rats. Female adult rats of Wistar strain were superovulated with a single injection of inhibin antiserum (inhibin-AS; 100 or 400 µl) or an injection of 20 IU eCG followed by an injection of 10 IU hCG. Untreated animals were served as control. Embryos were collected from oviducts or uteri on days 1-5 of pregnancy, and the number of embryos and implantation sites were observed. On day 1 of pregnancy, the 2-cell stage embryos were cultured and embryos from the 100 µl inhibin-AS group and the control group were transferred to recipient females to determine developmental competence. There were no significant differences between groups in fertilization rate. The numbers of normal embryos in the inhibin-AS treated groups were significantly higher than the control and the eCG-hCG treated groups throughout the days 1-4 of pregnancy. The number of implantation sites observed on day 5 of pregnancy in the inhibin-AS treated groups was significantly higher than both the control and the eCG-hCG treated groups. Furthermore, the rate of blastocysts development in vitro in the inhibin-AS treated groups and post-transfer viability in the 100 µl inhibin-AS group were comparable to those of the control group. These results indicate that immunoneutralization of endogenous inhibin is a new practical alternative for induction of superovulation as a substitiution for eCG-hCG method in the adult rats.
Key words:
Embryo •
Ovary •
Implantation •
Inhibin •
Ovulation
