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Molecular mechanism of gustatory transduction in taste cells

味觉细胞味觉转导的分子机制

基本信息

批准号：
01480433
负责人：
SATO Toshihide
金额：
$ 3.97万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

1. We investigated kinds of ionic channels and pumps and the gustatory transduction mechanisms in frog taste cells with electrophysiological techniques.2. We found voltage-gated Na channel and four types of K channels (Ca-activated ; delayed rectifier ; transient ; inward rectifier) in the taste cell membrane.3. Transduction of NaCl into a frog taste cell response is concerned with cation and anion channels of the apical receptive membrane and TTX insensitive Na channel of the basolateral membrane.4. Transduction of quinine-HCl into a frog taste cell response is concerned with a release of intracellular Cl^- through the apical receptive membrane.5. Transduction of galactose into the taste cell response is concerned with a release of intracellular OH^- or an entry of superficial H^+ or both through the apical receptive membrane.6. Transduction of HCl into the taste cell response is not concerned with channels and pumps at the basolateral membrane, but with Ca channels and proton pumps at the apical receptive membrane. The contribution of the former is much larger than that of the latter, and blocking the Ca channels with Cd^<2+> greatly reduced the acid-induced receptor potential.7. By simultaneous current recording and gustatory stimulation of the taste receptor membrane with a patch pipette, it was found that transduction of NaCl stimuli into the taste cell response is concerned with the NaCl-gated K^+ channels having a relatively low selectivity to monovalent cations.

1.采用电生理技术研究了蛙味觉细胞的各种离子通道和离子泵及其味觉信号转导机制.在味觉细胞膜上发现了电压门控性Na通道和四种类型的K通道（Ca激活的、延迟整流的、瞬时的、内向整流的）. NaCl对蛙味觉细胞的转导反应与顶端感受膜的阳离子和阴离子通道以及基底外侧膜的TTX不敏感Na通道有关.奎宁-HCl转导到青蛙味觉细胞的反应与细胞内Cl^-通过顶端感受膜的释放有关。将半乳糖传导到味觉细胞的反应与细胞内OH^-的释放或表面H^+的进入或两者通过顶端感受膜有关。HCl对味觉细胞的转导反应与基底膜上的通道和泵无关，而与顶端感受膜上的Ca通道和质子泵有关。前者的贡献远大于后者，并且用Cd^<2+>阻断Ca通道大大降低了酸诱导的受体电位.通过用贴片移液管同时记录电流和味觉刺激味觉感受器膜，发现NaCl刺激到味觉细胞反应的转导与NaCl门控的K^+通道对单价阳离子的选择性相对较低有关。