苦皮藤素Ⅳ和Ⅴ混合物对果蝇幼虫神经肌肉兴奋性接点电位的影响

利用细胞内微电极记录技术研究了杀虫植物苦皮藤Celastrus angulatus Max.中麻醉成分苦皮藤素Ⅳ和毒杀成分苦皮藤素Ⅴ混合物对果蝇Drosophila melanogaster 3龄幼虫腹纵肌神经肌肉兴奋性接点电位（EJPs）的作用。结果表明，苦皮藤素Ⅳ比例较高（Ⅳ∶Ⅴ= 3∶1）时对EJPs的影响与单用苦皮藤素Ⅳ差不多，而苦皮藤素Ⅴ比例较高（Ⅳ∶Ⅴ= 1∶1和1∶3）时可使EJPs阻断时间明显延长。根据以上结果初步认为，虽然苦皮藤素Ⅳ和Ⅴ单独对EJPs的阻断作用基本相似，但它们对突触谷氨酸受体通道的影响存在明显差异。

Effects of the mixture of celangulin Ⅳ and Ⅴ from Celastrus angulatus Max. on excitatory junction potentials of Drosophila melanogaster larvae

Celangulin Ⅳ and Ⅴ isolated from the root bark of the Chinese bittersweet, Celastrus angulatus Max. are the major active insecticidal ingredients of this plant. The mixed effects of celangulin Ⅳ and Ⅴ on insect neuromuscular excitatory junction potentials (EJPs) were studied by using the intracellular microelectrode recording on the ventral longitudinal body-wall muscle fibers of the 3rd instar larvae of Drosophila melanogaster. The results indicated that the effects of the mixture of celangulin Ⅳ and Ⅴ on EJPs of D. melanogasterlarvae, in which celangulin Ⅳ was in higher ratio, were same as that of celangulin Ⅳ. The blocking time of EJPs was delayed by the mixture of celangulin Ⅳ and Ⅴ, in which celangulinⅤ was in higher ratio. In conclusion, celangulin Ⅳ and Ⅴ could have different effects on glutamate potential of insect synapses.