关键词: 砷, 热休克蛋白70mRNA, 原位杂交, 胚胎, 神经毒性

Abstract: In situ hybridization histochemist ry ( ISHH) , scanning elect ron microscope (SEM) and microdissection were used to determine neuratoxicity and developmental toxicity and expression of HSP70mRNA during rat neurulation period in vivo. Fowllowing an increase in dose or active time of arsenic all indexes correlated with embryonic nervous system development and morphological differentiation were changed , which had an apparent dose2effect ralationship ( P < 0. 05) .At rophied and decreased microvilli , and cavernous damages of epidermic cells on embryonic brain were seen under SEM. The result of ISHH showed that arsenic could induce stress response of rat embryos. The incidence of open neural tube ( 35. 7 %) and gene overexpression of HSP70mRNA induced by 10mg/ kg arsenic were higher than that action of 4mg/ kg arsenic. It was the reason that HSP70 could have double action. Developmental and neural toxicity of different dose of arsenic was related to level of self2cont ral and synthesis of HSP70 in embryonic cells and which specific phase of embryonic developmental processes.

Key words: arsenic, HSP70mRNA, in situ hybridization, embryo, neuratoxicity