ABSTRACT Methomyl (MET) is a carbamate insecticide which is used as a substitute for organophosphorus compounds to protect crops against insects. The present study aims to evaluate the cytoprotection response of pigment cells and heat shock protein 70 (HSP70) after exposure to MET during the tadpole developmental stages of the Arabian toad, Bufo arabicus. Three developmental larval stages of the toad were selected and divided into two groups; Control and MET-exposed (MET-EX) tadpoles (10ppm). MET-EX tadpoles showed an increased number of pigment cells in the liver, kidney, anterior eye chamber, and skin tissues as compared to the control. The glycogen content in the developing liver and muscles (myotomes) of MET-EX tadpoles was decreased as compared to the control. In the MET-EX tadpoles, immunohistochemical staining showed an increase of HSP70 expression in the liver hepatocytes, the nucleated red blood cells (nRBC) in kidney glomeruli, the iridocorneal angle of anterior eye chamber, and the skin as compared to the control. The current study concluded that pigment cells and HSP70 represented a cytoprotecting response against MET insecticide during the organ development of B. arabicas tadpoles. Therefore, MET use should be regularly monitored in the environment to protect animals and human from exposure to this insecticide.

中文翻译：

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在阿拉伯蟾蜍器官发育过程中诱导色素沉着过度和热休克蛋白 70 对灭多威杀虫剂毒性的反应 (Heyden, 1827)

摘要 灭多威 (MET) 是一种氨基甲酸酯类杀虫剂，用作有机磷化合物的替代品，以保护作物免受昆虫侵害。本研究旨在评估在阿拉伯蟾蜍蝌蚪发育阶段暴露于 MET 后色素细胞和热休克蛋白 70 (HSP70) 的细胞保护反应。选择蟾蜍的三个发育幼虫阶段，分为两组；对照和 MET 暴露 (MET-EX) 蝌蚪 (10ppm)。与对照相比，MET-EX 蝌蚪在肝脏、肾脏、眼前房和皮肤组织中的色素细胞数量增加。与对照相比，MET-EX 蝌蚪发育中的肝脏和肌肉（肌节）中的糖原含量降低。在 MET-EX 蝌蚪中，免疫组织化学染色显示，与对照组相比，肝脏肝细胞、肾小球中的有核红细胞 (nRBC)、前眼房虹膜角膜角和皮肤中 HSP70 的表达增加。目前的研究得出结论，色素细胞和 HSP70 代表了在小粒芽孢杆菌蝌蚪器官发育过程中对 MET 杀虫剂的细胞保护反应。因此，应定期监测环境中 MET 的使用情况，以保护动物和人类免于接触这种杀虫剂。目前的研究得出结论，色素细胞和 HSP70 代表了在小粒芽孢杆菌蝌蚪器官发育过程中对 MET 杀虫剂的细胞保护反应。因此，应定期监测环境中 MET 的使用情况，以保护动物和人类免于接触这种杀虫剂。目前的研究得出结论，色素细胞和 HSP70 代表了在小粒芽孢杆菌蝌蚪器官发育过程中对 MET 杀虫剂的细胞保护反应。因此，应定期监测环境中 MET 的使用情况，以保护动物和人类免于接触这种杀虫剂。