多巴胺对鲫鱼视网膜H1型水平细胞上电压门控钙离子通道的调控特性  

Modulation of Dopamine on Voltage Gated Calcium Channel Expressed on H1 Horizontal Cell in Carp Retina

作　　者：朱文静[1] 吕婷[1] 龚海庆[1] 

机构地区：[1]上海交通大学生物医学工程系,上海200240

出　　处：《生物物理学报》2012年第10期837-847,共11页Acta Biophysica Sinica

基　　金：国家自然科学基金项目(30870836);上海交通大学分析测试中心资助项目~~

摘　　要：利用细胞内的钙离子成像技术,研究了多巴胺对鲫鱼视网膜H1型水平细胞上L型电压门控钙离子通道的调控特性。研究发现,在不同胞外pH(6.8、7.4、8.0)条件下,不同浓度多巴胺(50和500μmol/L、1 mmol/L)对L型电压门控钙离子通道均具有上调作用。50μmol/L多巴胺在不同pH下的上调程度没有显著性差异;高浓度多巴胺(500μmol/L和1 mmol/L)在pH8.0条件下比pH6.8和7.4条件下具有更显著的上调作用。这些结果表明,在鲫鱼视网膜H1型水平细胞上,多巴胺对电压门控钙离子通道的调控与胞外pH环境密切相关。在光照情况下,L型电压门控钙离子通道活性被相对高浓度多巴胺上调,并被胞外碱性环境协同增强。这种协同增强效应有助于阐明视网膜对光反应的信息传递机制。The modulatory effect of dopamine （DA） on L-type voltage gated calcium channel （L-VGCC） was examined using intracellular calcium imaging technique. It was found that in different pH conditions （pH6.8, 7.4, 8.0）, DA （50 μmol/L, 500 μmol/L, 1 mmol/L） up-regulated L-VGCC; 50 μmol/L DA had an up-regulation effect on L-VGCC, without significant difference in different pH conditions; in different pH conditions, high concentration DA （500 μmol/L, 1 mmol/L） up-regulated L-VGCC differentially, with greater regulation in pH8.0 than pH6.8 or 7.4, without significant difference between pH6.8 and 7.4 conditions. These results suggest that the modulatory effect of DA on L-VGCC is related to extracellular pH. In retinal light response, L-VGCC is up-regulated by relatively high concentration DA with collaborative enhancement of extracellular alkalization. This collaborative enhancement effects help to clarify the information transmission mechanism in retinal light response.

关 键 词：视网膜 水平细胞 多巴胺 电压门控钙离子通道 钙成像 

分 类 号：Q424[生物学—神经生物学]