苦皮藤素V对东方粘虫中肠细胞及其消化酶活性的影响

EFFECTS OF CELANGULIN V ON THE MIDGUT CELLS AND THE DIGESTIVE ENZYME ACTIVITIES OF MYTHIMNA SEPARATA (WALKE) LARVAE

苦皮藤素Ｖ是从杀虫植物苦皮藤ＣｅｌａｓｔｒｕｓａｎｇｕｌａｔｕｓＭａｘ．根皮中分离的一种对昆虫具有毒杀活性的新化合物。该文通过电镜观察和生化分析研究了其对东方粘虫Ｍｙｔｈｉｍｎａｓｅｐａｒａｔａ（Ｗａｌｋｅｒ）幼虫中肠组织及中肠主要消化酶活性的影响。电镜观察发现，中毒试虫的中肠细胞及其细胞器发生明显病变：柱状细胞顶膜微绒毛零乱、减少；线粒体肿胀，出现空白亮区，双层膜不完整；细胞质密度降低，细胞器排列紊乱；内质网池扩张，囊泡化，粗面内质网减少；杯状细胞杯腔变大，微绒毛减少。消化酶活性测定结果表明，中毒试虫中肠的蛋白酶、淀粉酶及脂肪酶的活性和正常虫相比，无显著变化。因此认为，苦皮藤素Ｖ主要作用于中肠细胞的质膜及其内膜系统。

\ Celangulin V isolated from the root bark of the plant Celastrus angulatus is a new insecticidal compound. The effects of celangulin V on the midgut cells and digestive enzyme activities of Mythimna separata larvae were determined by means of electron microscopy and biochemical analysis. It was observed that the midgut cells and their organelles of poisoned larvae exhibited distinct pathological changes: the microvilli of the column cell were disordered and the number of microvilli was decreased markedly, the basal infolding of the cell membrane was enlarged, in which the number of mitochondria was decreased. It was also observed that mitochondria had irregularly enlarged, the bilayer membrane was not intact, the cisternae of rough endoplasmic reticulum were distended; the cavity of goblet cell was enlarged, in which the microvilli came off. The results of biochemical analysis showed that the activities of protease, amylase and lipase of the poisoned larval midgut had no significant changes compared with the normal larval midgut. It is thus suggested that celangulin V might act on the plasmalemma and the organelle membrane of the midgut cells.