Protection from oxidative stress by thioredoxin and superoxide dismutase of mouse embryos fertilized in vitro.
A low oxygen tension and superoxide dismutase (SOD) have been demonstrated to promote development of embryos in vitro. In this study, we evaluated the effects of thioredoxin (TRX), a powerful protein disulphide reductase, on the development of mouse embryos fertilized in vitro. Moreover, to clarify the difference between the embryo-protecting mechanisms of TRX and SOD, as well as the critical periods of their actions, we carried out experiments in which we transferred embryos among three different media: basic, TRX- and SOD-supplemented. The rates of 4-cell, blastocyst and expanded blastocyst formation in TRX- (53%, 40% and 34% respectively), or SOD- (59%, 29%, 22%) supplemented media were significantly higher than those (28%, 4%, 0%) in the basic medium. The results of the transfer of embryos using basic and TRX-supplemented media indicated an increase in the rate of expanded blastocysts when TRX was applied from 7 to 30 h, and especially from 18 to 24 h after insemination. In contrast, the results of the transfer of embryos using basic and SOD-supplemented media indicated that SOD, which was also most effective when applied from 7 to 30 h after insemination, had some effects after 30 h. These results indicate that TRX and SOD promote the in-vitro development of mouse embryos fertilized in vitro, which suggests that protection of embryos from oxidative stress is a prerequisite for their development in vitro. SOD and TRX provide protection from oxidative stress by different mechanisms.
Nonogaki
T
T
Department of Gynaecology and Obstetrics, Faculty of Medicine, Kyoto University, Japan.
Noda
Y
Y
Narimoto
K
K
Umaoka
Y
Y
Mori
T
T
D000818:Animals; D003470:Culture Media; D005314:Embryonic and Fetal Development / Q000187:drug effects*; D005260:Female; D005306:Fertilization / Q000187:drug effects; D005307:Fertilization in Vitro; D008297:Male; D051379:Mice; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism*; D013879:Thioredoxins / Q000494:pharmacology*
D003470:Culture Media; D013879:Thioredoxins; D013482:Superoxide Dismutase