人们每天都在消耗能量,每天需要不停的吃饭来补充能量,饭吃下去变成能量却需要盐将一部分调用上来,这就是我们必须吃盐的原因,盐味咸,中医讲咸能入肾,能将肾气调起来维持我们正常的活动和功能。
哺乳动物不喜欢高浓度的盐,但却被低浓度的钠所吸引。对小鼠来说,后一种行为能被离子通道抑制药物“氨氯吡脒”阻断。现在,通过基因工程方法使其味觉受体神经元中失去该药物的目标钠离子通道“ENaC”的小鼠,被发现既不能感受盐,也没有对钠味道的反应。所以,对钠的感受,就像其他四个味觉形态(甜味、酸味、苦味和鲜味)一样,是由专门的味觉受体细胞调控的。不过,因为钠的感受在灵长类中对“氨氯吡脒”是不敏感的,所以这一发现与我们感觉咸味(盐)的能力有什么关系仍不清楚。(生物谷Bioon.com)
生物谷推荐原文出处:
Nature 464, 297-301 (11 March 2010) | doi:10.1038/nature08783
The cells and peripheral representation of sodium taste in mice
Jayaram Chandrashekar1,4, Christina Kuhn2,5, Yuki Oka1,5,4, David A. Yarmolinsky1,4, Edith Hummler3, Nicholas J. P. Ryba2 & Charles S. Zuker1,4
1 Howard Hughes Medical Institute and Departments of Neurobiology and Neurosciences, University of California at San Diego, La Jolla, California 92093-0649, USA
3 National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, USA
3 Pharmacology and Toxicology Department, Faculty of Biology and Medicine,
4 University of Lausanne, CH-1005 Lausanne, Switzerland
5 These authors contributed equally to this work.
Salt taste in mammals can trigger two divergent behavioural responses. In general, concentrated saline solutions elicit robust behavioural aversion, whereas low concentrations of NaCl are typically attractive, particularly after sodium depletion1, 2, 3, 4, 5. Notably, the attractive salt pathway is selectively responsive to sodium and inhibited by amiloride, whereas the aversive one functions as a non-selective detector for a wide range of salts1, 2, 3, 6, 7, 8, 9. Because amiloride is a potent inhibitor of the epithelial sodium channel (ENaC), ENaC has been proposed to function as a component of the salt-taste-receptor system1, 3, 6, 7, 8, 9, 10, 11, 12, 13, 14. Previously, we showed that four of the five basic taste qualities—sweet, sour, bitter and umami—are mediated by separate taste-receptor cells (TRCs) each tuned to a single taste modality, and wired to elicit stereotypical behavioural responses5, 15, 16, 17, 18. Here we show that sodium sensing is also mediated by a dedicated population of TRCs. These taste cells express the epithelial sodium channel ENaC19, 20, and mediate behavioural attraction to NaCl. We genetically engineered mice lacking ENaCα in TRCs, and produced animals exhibiting a complete loss of salt attraction and sodium taste responses. Together, these studies substantiate independent cellular substrates for all five basic taste qualities, and validate the essential role of ENaC for sodium taste in mice.