PROGRESSIVE EFFECT OF ALPHA-PHENYL-N-TERT-BUTYL NITRONE (PBN) ON RAT EMBRYO DEVELOPMENT IN-VITRO

In the present study we demonstrated the effects of the spin-trapping agent alpha-phenyl-N-tert-butylnitrone (PEN) on the in vitro developme nt of rat embryos at the early stage. In rat embryos, PEN increased th e speed of the first cleavage and had no toxicity during pregnancy aft er embryo culture. These results showed that reactive oxygen species ( ROIs) that were formed by activating molecular oxygens through redox r eactions regulated the speed of development for early-stage embryos. T hus, PEN caused a decrease in the level of ROIs and toxicity and an in increase in the level of the development of rat embryos. On the other hand, PEN could not decrease the 2-cell block in vitro nor increase t he blastulation rate, in contrast to the fact that a scavenger of supe roxide anions, SOD, is effective in doing so for mouse embryos. From t hese results it was concluded that free radicals play an important rol e in the in vitro development of rat embryos at the early stage, but p lay no role in the decrease of the 2-cell block or their blastulation rate. It should be noted that PEN had no toxicity for embryonic develo pment at the 2-cell stage. Published by Elsevier Science Inc.