Radiation ; Whole embryo culture ; Congenital malformation ; Rat
Abstract
It is known that radiation can induce various kind of mutations, cancers and congenital malformations Day 9 rats embryos were cultured by whole embryo culture method and irradiated 0 1 0 5 2 and 5 Gy at day 10 to study the effect of radiation on the development of rat embryos Haversting after 48 hours culture, the morphological changes andapop-tasis were Investigated In addition, we assessed the expression patterns of pS3, WAFI, Bc1-2, Bcl-x and Bax Compared to the control group, no remarkable morphological changes were observed 10 the low dosage group (0 1 and 05 Gy) But at high dosage group (2 and 5 Gy), growth was retarded and the heart beats were weak The crown rump length, the number of somltes, and branchial arch were decreased and the rotation of embryo and development of Otic pit and lens pit, and upper 11mb bud was delayed significantly Especially in the 5 Gy group the most of external morphology were difficult to discriminate In histological observations, high dosage group showed marked mcrease in the number of apoptotic bodies In the optic cup, tngeminal ganglion, pharyngeal arches, heart and small Intestine In western blot analysis, Bcl-x and Bax were not expressed In all groups Expression level of Bcl-2 was constant regardless of the amount of radiation Expression level of p53 and W AFI Increased slgnificantly in accordance with the increasing amount of radiation Especially, WAFI was expressed 72, 63, 99 and 11 3 folds more than the control groups when embryos were exposed to 0 I, 0 5, 2 and 5 Gy, respectively Considering W AFI arrests cell cycle, we concluded that cell cycle was affected most sensitively to radiation Injury From these results, rarnation showed growth retardation, decrease In protein synthesis, increase in apoptosls and expression of related genetic inatenals These results may be used as a standard to test the effect of drugs for reducing and protecting agents against deterious effect of rarnation in developing embryo and fetus