大麻素对人和小鼠视网膜神经节细胞GABA电流的调控差异  

Modulation of cannabinoid to GABA currents in retinal ganglion cells in human and mice

作　　者：罗雪[1] 刘诗亮[1] 江梦南 沈雨濛 胡单萍 沈吟[1] 

机构地区：[1]武汉大学人民医院眼科中心,武汉430060

出　　处：《第三军医大学学报》2015年第12期1188-1192,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金面上项目(81270998;81470628)~~

摘　　要：目的比较人和小鼠视网膜内源性大麻素类受体1(cannabinoid receptor,CB1)的表达差异,观察大麻素受体激动剂WIN55212-2对不同种属视网膜神经节细胞GABA电流的调控作用。方法采用冰冻切片免疫荧光染色,观察CB1受体在视网膜中的表达。制备视网膜薄片,行全细胞膜片钳记录。在神经节细胞上给予100μmol/L GABA快速加药诱导出电流IGABA,而后观察孵育大麻素受体激动剂WIN55212-2时GABA诱导的IGABA及同时孵育WIN 55212-2和大麻素受体拮抗剂SR141716A的电流IGABA。结果人和小鼠视网膜CB1受体的分布有所不同,人的内核层、外核层、神经节细胞层有显著的CB1表达,但小鼠CB1受体主要表达在内网状层、外网状层上;膜片钳结果显示不管是在人还是在小鼠的视网膜上,孵育WIN55212-2后的GABA诱导电流幅度均有显著减小。不同的是,在人视网膜神经节细胞上,WIN55212-2明显减慢了GABA电流的反应速度,表现在电流达峰时间明显延长,恢复时间缩短(P<0.05)。WIN55212-2对小鼠视网膜神经节细胞GABA的反应速度无明显差别(P>0.05)。结论CB1受体在人和小鼠视网膜中有差异性分布,对神经节细胞的GABA电流影响也不同。孵育WIN55212-2可抑制人和小鼠神经节细胞GABA电流幅度,但仅对人的神经节细胞的GABA电流的动力学速度有影响。Objective To compare the expression of endogenous cannabinoid receptor 1（ CB1） in human and mouse retinal ganglion cells and observe the modulation of CB1 receptor agonist WIN55212-2 toγ-aminobutyric acid（ GABA） currents. Methods Immunofluorescence assay was applied to study the expression pattern of CB1 receptors in the retina. Whole-cell patch-clamp technology was used to record GABA currents in the retinal ganglion cells after applying 2 μmol / L WIN55212-2 or 2 μmol / L WIN55212-2 ＋4 μmol / L SR141716A（ CB1 receptor antagonist）. Results CB1 receptors were expressed in the human outer nuclear layer,inner nuclear layer and ganglion cell layer,while expressed in the mouse inner plexiform layer and outer plexiform layer. The patch-clamp recording results showed that WIN55212-2 significantly reduced the GABA current amplitude in the human and mouse retinal ganglion cells（ P 〈 0. 05）. The application of WIN55212-2 resulted in significant changes of GABA current kinetics,including low reaction speed,long current peak time and short recovery time,in human retina,but not in mouse retina（ P 〉 0. 05）.Conclusion CB1 receptors are expressed abundantly and differentially in the human and mouse retina,and have different effects on the GABA currents in the retinal ganglion cells. WIN55212-2 suppresses the GABA current amplitude in the human and mouse retinal ganglion cells,but modulates the GABA current dynamics only in human retinal ganglion cells.

关 键 词：人视网膜 大麻素受体 神经节细胞 全细胞膜片钳技术 

分 类 号：R322.91[医药卫生—人体解剖和组织胚胎学] R962[医药卫生—基础医学]