家蚕ENF肽致麻痹活性的定量评估（英文）  

Quantitative evaluation of the paralytic activity of an ENF peptide in Bombyx mori

作　　者：王菲[1] 董世峰[1] 宋亮[1] 胡杰[1] 夏庆友[1] WANG Fei;DONG Shi-Feng;SONG Liang;HU Jie;XIA Qing-You(State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China)

机构地区：[1]西南大学家蚕基因组生物学国家重点实验室,重庆400716

出　　处：《昆虫学报》2017年第10期1114-1119,共6页Acta Entomologica Sinica

基　　金：国家自然科学基金项目(31672495);重庆市基础与前沿研究计划项目(CSTC2014JCYJA80010)

摘　　要：【目的】麻痹肽(paralytic peptide,PP)是一种在鳞翅目昆虫血淋巴中鉴定到的Glu-Asn-Phe(ENF)肽,将其注入幼虫体内会引发快速僵化的紧张性收缩。本研究旨在确定PP引起家蚕Bombyx mori幼虫活体收缩的最适剂量和最大收缩幅度,并检测诸如背血管搏动速率和离子浓度等可能伴随收缩现象的其他生理指标的变化。【方法】向家蚕5龄幼虫注射不同剂量的PP后,监测其体长收缩幅度和背血管博动速率,并用原子吸收光谱测定血淋巴、脂肪体和肠道的离子浓度。【结果】浓度为50 ng/g动物时,PP引发最有力收缩且不会导致家蚕死亡。最大收缩出现在注射后4~5 min内,同时肠道出现不正常扭曲以及背血管脉动速率下降。此外,细胞外Ca^(2+)是收缩所必需的,PP刺激还导致血淋巴中Cl^-浓度急剧下降而后缓慢恢复。【结论】PP的致麻痹活动不仅引起身体收缩,还会影响家蚕幼虫的肠道和背血管的脉动,而且破坏Cl^-的体内平衡。研究结果为在动物模型中研究PP的生理功能提供参考。【Aim】 A Glu-Asn-Phe （ENF） peptide, paralytic peptide （PP） identified in several lepidopteran hemolymph induces rapid and rigid paralysis defined by a tonic contraction when injected into larvae. This study aims to determine the optimal amount and maximum contraction that PP induces in live larvae of the silkworm, Bombyx mori, and to examine the possible change of other physiological index, such as pulse velocity and ion concentration which might accompany the contraction. 【Methods】 The intensity of body contraction and pulse velocity were monitored after injection of various amounts of PP into the body of the 5th instar larvae. And the ion concentrations in hemolymph, fat body and digestive tube were measured by atomic absorption spectroscopy. 【Results】 PP at the concentration of 50 ng/g animal triggered the most potent contraction with no lethal effect. The maximum body contraction was seen between 4 and 5 min after injection. Digestive tube distortion was found to accompany body wall contraction, and pulse velocity decreased when the body reached the maximum contraction. In addition, extracellular Ca^2＋ was required for the contraction and PP also stimulated a sharp decrease then a slow recovery of Cl^- concentration in hemolymph. 【Conclusion】 The paralytic activity of PP not only affects the body wall, but also digestive tube and dorsal vessel of silkworm larvae, and is associated with disruption of Cl^- homeostasis. Our results will provide reference for studying the physiological role of PP in an animal model.

关 键 词：家蚕 麻痹肽 收缩 离子浓度 脉动速率 

分 类 号：Q966[生物学—昆虫学]