A PHYSICOCHEMICAL INVESTIGATION OF TASTE

该提案涉及哺乳动物味觉的转导机制 接待 一种检测促味剂在大肠杆菌中作用的新方法 引入了单细胞水平。 该方法允许使用促味剂， 味蕾的正常味觉敏感区域，同时 记录细胞电反应的时间。 录音是使用 膜片钳技术 通过这些方法， 检查大鼠舌前部的细胞。 单个 对大鼠鼓索的纤维分析表明存在细胞 在细胞顶端有高度选择性的钠离子传导 膜的 也应该有选择性较低的细胞反应，以各种 盐和酸。 一个细胞类型的目录将被制作来测试这个 假说. 改变细胞内电位的动力学将是 在正常化学刺激条件下进行研究。 可能的 将注意到动作电位的存在，并且细胞的动力学 将进行适应性研究。 初步数据显示， 一些味觉细胞的膜具有阿米洛利阻断传导。 的 这些阿米洛利敏感性顶端膜电导的离子特异性 将被审查。 cAMP可能参与甜味 将探索转导。 这将在单细胞水平上完成， 并且还使用了活体大鼠模型，其中鼓索对 将通过跨上皮电位的变化测量蔗糖，或 电流欠压钳位。 初步数据显示，基底外侧 膜电导在蔗糖刺激期间被阻断。 的 阿米洛利-阻断钠表达的调节问题 将是地址。 在钠缺乏的大鼠中， 可以通过钠调节实现调节的证据 荷尔蒙 我们将探讨这种可能性电生理在 细胞水平和活大鼠模型。 心房利钠因子， 通过cGMP起作用，是可能的调节物质之一。 味道有 决定食物摄入量的主要因素。 条件和物质 调节其表达的基因将在以下领域产生强烈影响： 钠敏感性高血压和进食障碍如肥胖症。

The proposal deals with the mechanism of transduction in mammalian taste reception. A new method for detecting the effects of tastants at the single cell level is introduced. The method permits tastants to be applied to the normal taste-sensitive regions of the taste-bud while at the same time recording the cell electrical response. Recordings are made using patch-clamp technology. With these methods the characteristics of the cells in the anterior part of the rat tongue will be examined. Single fiber analysis of the rat chorda tympani suggests the existence of cells that will have a highly selective sodium ion conductance in the cell apical membrane. There should also be less selective cells reactive to various salts and acids. A catalog of cell types will be made to test this hypothesis. The kinetics of the changing intracellular potential will be studied under conditions of normal chemical stimulation. The possible presence of action potentials will be noted and the kinetics of cellular adaptation will be studied. Preliminary data show that the apical membranes of some taste cells have amiloride-blockade conductances. The ion specificity of these amiloride-sensitive apical membrane conductances will be examined. The possible involvement of cAMP in the sweet taste transduction will be explored. This will be done on the single cell level, and also using a live-rat model in which the chorda tympani response to sucrose will be measured with changes in the transepithelial potential or current under voltage clamp. Preliminary data indicate that a basolateral membrane conductance is blocked during stimulation by sucrose. The question of the regulation of the expression of amiloride-blockade sodium conductances will be addresses. Among sodium-deprived rats there is evidence that regulation may be effected through sodium-regulating hormones. We shall explore this possibility electrophysiologically at the cellular level and with a live-rat model. Atrial natriuretic factor, acting via cGMP, is one of the possible regulatory substances. Taste is a major factor in determining food intake. The conditions and substances that modulate its expression will have a strong impact in the areas of sodium-sensitive hypertension and feeding disorders such as obesity.