河蟹眼柄神经内分泌细胞Glu受体研究  

RESEARCH ON THE GLUTAMATE GATED CHANNELS IN THE NEUROSECRETORY CELLS OF MTXO IN THE EYESTALKS OF ERIOCHEIR SINENSIS

作　　者：孙金生[1] 高春蕾[2] 相建海[2] 

机构地区：[1]天津师范学院生物系 [2]中国科学院海洋研究所,青岛266071

出　　处：《水生生物学报》2004年第6期647-652,共6页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金资助项目 (3 0 2 710 19);国家"973"重点基础研究资助项目(G19990 12 0 0 7)资助

摘　　要：作者采用全细胞膜片钳技术测定了中华绒螯蟹 (Eriocheirsinensis)眼柄视神经节端髓X器官 (MTXO)神经内分泌细胞对 0 0 1— 10mmol/L谷氨基酸 (Glu)的反应 ,并结合药理学方法进行了Glu受体研究。结果表明 ,Glu激活A型和B型细胞离子型Cl-通道蛋白受体 ,诱导快速激活、快速失活的配体门控Cl-通道电流 (IGlu)。依据内外液的Cl-浓度比例引发去极化或超极化反应 ,继续施加Glu ,细胞快速出现脱敏反应 ;去除Glu后 ,细胞约需 2 0s恢复对Glu的敏感状态。IGlu幅值呈浓度依赖性 ,量 效关系曲线呈线形 ,激活阈值为 0 0 1mmol/L ,约 5mmol/L达到饱和。河蟹眼柄神经内分泌细胞IGlu明显受到Cl-通道阻断剂picrotoxin(0 5mmol/L)抑制 ;对离子型Glu受体激动剂Quisqualate、Kainate、NMDA、AMPA不敏感。Ibotenicacid(IA)可模拟Glu诱导快速激活、快速脱敏的Cl-电流 ,并与Glu产生交互脱敏作用。Glu和GABA对河蟹眼柄神经内分泌细胞无交叉脱敏和交叉激活作用 ,甘氨酸 (Gly)没有诱导细胞产生任何反应 ,提示中枢神经系统通过Glu和GABA两套系统实现对眼柄神经内分泌系统的精确调控。The X-organ sinus gland is a major peptidergic neurosecretory system in crustacean,analogous to the vertebrate hypothalamoneurohypophyseal system.Chinese mitten-handed crab ( Eriocheir sinensis )X-organ located on the ventral surface of terminalia in the eyestalk,named MTXO.Three types of neurosecretory cells dissociated from MTXO had been identified on the basis of shape,size and outgrowth fashion.The cell type A and cell type B were immunoactive to anti-CHH and anti-MIH serum respectively.In the present paper,the whole-cell patch clamp technique was used to examine the responses of MTXO neurosecretory cells to rapid application of glutamic acid(Glu)and the Glu receptor characteristics.The results suggested that glutamate activated a ionotropic Cl - channel receptor and evoked depolarization or hyperpolarization in the type A and type B neurosecretory cells in response to the Glu (1mmol/L)depending on the [Cl -] 0/[Cl -] i ratio.Under voltage clamp mode,the transient inward Cl - channel currents(I Glu )were resolved in responses to Glu(0 01—5mmol/L).The size of Glu currents were related to the Glu concentration,Dose-responses curve showed line shape,with a just-discernable effect at 0 01mmol/L and near-saturation at 5mmol/L. During continued Glu perfusion, the responses declined more quickly for higher concentration.When the desensitization had occurred,it could not be overcome by application of higher concentration.The recovery required 20s for type A and type B cells after washing with standard extracellular solution.The Glu currents had reversal potentials that followed Nernst Cl - potentials when [Cl -] was varied.The pharmacological results revealed that the GABA receptor of the crab neurosecretory cells were sensitive to the Cl - channel blocker picrotoxin(0 5mmol/L),insensitive to ionotropic Glu receptor agonist,Quisqualate、Kainate、NMDA、AMPA.Ibotenic acid (IA)was proved to be an effective agonist on the cell type A and B,producing inward currents that showed rapid desensiti

关 键 词：河蟹 眼柄 神经内分泌细胞 中华绒螫蟹 L谷氨基酸 受体 全细胞膜片钳技术 

分 类 号：Q959.223[生物学—动物学] Q421