Development of Model System for Radiation Induced Congenital Malformations by Whole Embryo Culture / 체질인류학회지

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 and apoptosis were investigated. In addition, we assessed the expression patterns of p53, WAF1, Bcl -2, Bcl -x and Bax. Compared to the control group, no remarkable morphological changes were observed in the low dosage group (0.1 and 0.5 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 somites, and branchial arch were decreased and the rotation of embryo and development of otic pit and lens pit, and upper limb 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 increase in the number of apoptotic bodies in the optic cup, trigeminal 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 WAF1 increased significantly in accordance with the increasing amount of radiation. Especially, WAF1 was expressed 7.2, 6.3, 9.9 and 11.3 folds more than the control groups when embryos were exposed to 0.1, 0.5, 2 and 5 Gy, respectively. Considering WAF1 arrests cell cycle, we concluded that cell cycle was affected most sensitively to radiation injury. From these results, radiation showed growth retardation, decrease in protein synthesis, increase in apoptosis and expression of related genetic materials. These results may be used as a standard to test the effect of drugs for reducing and protecting agents against deterious effect of radiation in developing embryo and fetus.

Apoptosis induced by changes in the temperature during whole embryo culture of postimplantation rat embryos / 대한해부학회지

It has been reported that heat shock (43degrees C) induces an episode of cell death in developing central nervous system as part of pathogenesis leading to abnormal growth and development. Cell death induced by heat shock is likely to occur by a process termed apoptosis. On the other hand, protective role of mild heat shock on heat shock-induced apoptosis has also been suggested. In this study, the effect of 43degrees C heat shock on the induction of apoptosis was investigated in detail firstly by determining internucleosomal DNA fragmentation (DNA laddering) and secondly by determining apoptotic bodies using TUNEL (TdT-mediated dUTP-biotin nick end labeling). In addition, the effect of mild heat shock (42degrees C) on the apoptotic process was examined. In order to modulate the environmental temperatures of the developing embryos, we used whole embryo culture technique. DNA fragmentation and apoptotic body was induced a little by 42degrees C exposure but embryos exposed to 43degrees C showed strong DNA fragmentations. In comparison, the amount of DNA fragmentation was significantly reduced in embryos with 42degrees C pretreatment than 43degrees C group. In the control embryos (37degrees C exposure), basal levels of DNA fragmentation and apoptotic bodies were observed. From this study, it was evident that thermotolerance could protect the early postimplantation embryos from hyperthermia.

Experimental Study on Developmental Toxicity of AlCl_3 to Rats' Embryo in Vitro / 环境与健康杂志

re To understand the developmental toxicity of aluminum and its mechanism. Methods The embryos of SD rats at the 9. 5th day after gestation were explanted and cultured in a whole-embryo culture system with exposure to AlCl3 at Al3+ concentrations of 0.6, 0.9, 1.2, 3.0, 6.0 and 9.0 ?g/ml for 48 hours. Using Brown's mor-phological scoring system, yolk sac diameter, crown-rump length, head length and embryonic dry weight were mea-sured. Results A certain dose-effect relationship (r= - 0.890? 0.973, P

Effects of Hydrolysis and Polymerization of Aluminum Salt in Water Solution on Developmental Toxicity in Rats in Vitro / 环境与健康杂志

Objective To explore the effects of chemical reaction of aluminum salt in water solution on developmental toxicity Methods Inhibiting actions on embryo growth and development,and organ morphogenetic differentiation in rats induced by newly prepared and 11 5 month stored aluminum sulfate solution were observed and compared using whole embryo culture method in rats Results Both of the two observed solutions showed a certain embryo toxicity and teratogenicity The toxicity of stored solution decreased significantly compared with that of newly prepared solution At the same concentration of aluminum,the total Brown's morphogenetic score reflecting the every index of embryo growth and development and organ morphogenetic differentiation,the incidence rates of terata and the number of dead embryos were significant lower in rats exposed to stored solution compared with those exposed to newly prepared solution,especially the morbidity of embryos Conclusion The complexation reaction between aluminum ions (Al 3+ ) and water molecules in stored aluminum sulfate solution resulted in the changes of existing state of Al 3+ and its decreasing developmental toxicity to rats

Effects of Aluminum Sulfate on GSH Activity and Membrane Lipid Fluidity of Visceral Yolk Sac Cell of Mouse Embryo in Vitro / 环境与健康杂志

Objective To explore the developmental toxicity of aluminum sulfate and its mechanism. Methods 8.5-day-old embryos of Kunming mice were explanted and cultured in a whole embryo culture system with Al 3+ concentrations of 0.6, 0.9, 1.2, 3.0, 6.0, 9.0 ?g/ml for 48 h. Each viable embryo was evaluated using Maele-Fabry scoring system, and visceral yolk sac diameter, crown-rump and head length, and embryo dry weight were measured, as well as GSH activity in embryonic tissue by using 5,5-dithion-bis-2-nitrobenzoic acid (DTNB), and membrane lipid fluidity of visceral yolk sac cell by DPH fluorescence polarization technique. Results Al 2(SO 4)3 at Al 3+ concentration of 3 ?g/ml resulted in significant inhibition of development of embryos and differentiation of organs, and increasing prevalance rate of abnormal embryos including open neural tube, small head abnormality and deficit in flexion. At Al 3+ concentration of 6.0 ?g/ml, the activity of GSH and the membrane lipid fluidity of visceral yolk sac decreased significantly. In a certain degree, the dose-effect(response) relationship were observed in the above hazardous effects induced by Al 2(SO 4)3. Conclusion Al 2(SO 4)3 presented potential teratagenicity and embryotoxicity, which might be associated with the decreases of the membrane lipid fluidity of visceral yolk sac and the activity of GSH both induced by Al 2(SO 4)3.