左旋精氨酸对兔眼AⅡ无长突细胞与开放性视锥型双极细胞间示踪剂藕连的调控研究  

Modulation of tracer coupling in AⅡ amacrine cells and ON cone bipolars of rabbit retina by L arginine

作　　者：夏晓波[1] StephenL.Mills 黄佩刚[1] 蒋幼芹[3] 

机构地区：[1]中南大学湘雅医院眼科,长沙410008 [2]Department of Ophthalmology and Visual Science,Houston Medical School,University of Texas [3]中南大学湘雅二医院眼科

出　　处：《中华眼科杂志》2003年第4期215-219,共5页Chinese Journal of Ophthalmology

基　　金：美国国家卫生研究院基金资助项目 (Ey10 12 1;Ey10 60 8)

摘　　要：目的　探讨兔眼视网膜AⅡ无长突细胞 (AⅡamacrinecell,AⅡ AC)和开放性视锥型双极细胞 (onconebipolarcell,ON CB)间缝隙连接通道的相对通透性及左旋精氨酸对通道的调节。方法　单个AⅡ AC显微注射神经生物素 (neurobiotin ,NB)后 ,采用共焦显微镜测定以上两类异源型细胞群中NB的分布 ,并用 4mmol/L左旋精氨酸对其进行调节。然后用兔抗Calretinin抗体对注射后的视网膜进行免疫组织化学染色。结果　藕连的ON CB中的NB的浓度低于藕连的AⅡ AC中NB的浓度。与藕连的AⅡ AC比较 ,左旋精氨酸选择性的减少了与AⅡ AC藕连的ON CB中的NB的浓度(t=2 5 11,P <0 0 5 )。AⅡ AC被Calretinin抗体染色阳性。结论　相对于AⅡ AC和ON CB间可能的异源型缝隙连接 ,NB较易通过AⅡ AC间的同源型缝隙连接。左旋精氨酸可能使cGMP浓度升高而作用于双极细胞侧的缝隙连接 ,选择性的减少了这种双极细胞的示踪剂标记。Objective To determine the relative permeability of the gap junction pathways in AⅡ amacrine cells and ON cone bipolar cells of rabbit retina, and its modulation by L arginine Methods The distribution of neurobiotin across the heterologous cell assembly was measured using the confocal microscope after microinjecting neurobiotin into a single AⅡ amacrine cell Modulation of the tracer coupling by 4 mmol/L L arginine was also observed Rabbit anti calretinin antibody was used to stain the retina injected with neurobiotin Results Average neurobiotin concentration in the coupled ON cone bipolar cells was lower than that in the coupled AⅡ amacrine cells L arginine selectively reduced the concentration of neurobiotin in the ON cone bipolar cells, this effect was more prominent than that observed in the AⅡ amacrine cells ( P <0 05) AⅡ amacrine cells stained with anti calretinin antibody Conclusions Neurobiotin can pass easily through homologous AⅡ/AⅡ cells gap junctions as compared to the heterologous AⅡ/bipolar cells gap junctions L arginine reduces the labeling of neurobiotin in ON cone bipolar cells to a greater degree than in AⅡ amacrine cells The pathway of this effect is probably by increasing the level of cGMP and acting at the bipolar cell side of this gap junction

关 键 词：左旋精氨酸 兔眼AⅡ 无长突细胞 开放性视锥型 双极细胞 间示踪剂 藕连调控 视网膜 

分 类 号：R77[医药卫生—眼科]