虾夷扇贝毒素对ICR小鼠小脑浦肯野细胞毒性作用的初步研究

Preliminary studies on toxicity induced by yessotoxin(YTX) on Purkinje cells from the cerebellum of ICR mice

以雌性ICR小鼠为研究对象,尾静脉注射虾夷扇贝毒素24h后处死,通过脑组织切片,苏木精伊红染色、甲苯胺蓝染色以及钙结合蛋白S-100免疫染色,研究了虾夷扇贝毒素对小鼠浦肯野细胞的毒性作用。结果表明,尾静脉注射虾夷扇贝毒素的小鼠小脑浦肯野细胞细胞质有明显变化,同时在光学显微镜下观察到细胞核有收缩而用钙离子结合蛋白S-100的免疫荧光染色结果表明,虾夷扇贝毒素作用后,小鼠浦肯野细胞的S-100蛋白表达增多,而其他组织则没有明显变化。浦肯野细胞形态学以及细胞内钙离子结合蛋白的变化说明虾夷扇贝毒素可能对神经细胞有毒性作用。

Yessotoxin （YTX） and its analogues are disulfated polyether compounds which have been concerned more in seafood quality monitoring and shellfish industries recently. Many studies on the toxicity of YTXs had been carried out, but the results showed apparent discrepancies. Just these discrepancies have encouraged many researchers to study the mechanism by which YTX exerts its action, such as what the target tissues are, what the pattern of the mode and precise mechanism of action are. However, the process still remains largely unclear. This paper aims to study the toxicity of yessotoxin and analyze the possible action mechanism to the nerve tissue by using histological and immunohistochemical methods. 24 hrs after tail intravenous injection with yessotoxin, the female ICR mice were killed and cerebella tissue was fixed and sliced. Hematoxylin-eosin （HE） staining used to study the effects of yessotoxin on nerve cells shows obvious morphological changes of Purkinji cells in cerebella tissue, such as shrinkage, deep staining of cytoplasm, non-mottled Nissl＇ s body and so on. According to the immunohistochemical staining of calcium binding protein S-100, there is a more positive response to YTX in test group than in control group. It seems that YTX induces the increase of Ca2＋ concentration in Purkinji cells of mice cerebellum; it is identical to the results of other researches. To our knowledge, this is the first report of：the toxicity of YTX on nervous system in China, but the work is preliminary and further studies are needed, such as the relationship between the action mechanism of YTX and Ca2＋ signal transduction.