Fat and carbohydrate preferences in mice:: the contribution of α-gustducin and Trpm5 taste-signaling proteins
Fat and carbohydrate preferences in mice:: the contribution of α-gustducin and Trpm5 taste-signaling proteins
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DOI：
10.1152/ajpregu.00364.2007
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发表时间：
2007-10-01
影响因子：
2.8
通讯作者：
Margolskee, Robert F.
中科院分区：
文献类型：
--
作者：
Sclafani, Anthony;Zukerman, Steven;Margolskee, Robert F.
Trpm 5和α-味蛋白是糖、氨基酸和苦味化合物的味道转导的关键。本研究使用Trpm 5敲除（Trpm 5 KO）和α-gustducin敲除（Gust KO）小鼠研究了这些信号蛋白在偏好脂肪，淀粉和淀粉衍生多糖（Polycose）中的作用。在最初的两瓶试验（24小时/天）中，Trpm 5 KO小鼠对大豆油乳剂（0.313-2.5%）、多糖溶液（0.5-4%）或淀粉混悬液（0.5-4%）无偏好。Gust KO小鼠对多糖的偏好减弱，但它们对大豆油和淀粉的偏好与C57 BL/6 J野生型（WT）小鼠相当。Gust KO小鼠更喜欢淀粉而不是多糖，而WT小鼠则相反。在使用大豆油乳剂（Intraperoid）和多糖溶液的广泛经验后，Trpm 5 KO小鼠产生了与WT小鼠相当的偏好，尽管它们的绝对摄入量仍然受到抑制。类似地，Gust KO小鼠随着经验发展出强烈的多糖偏好，但它们的摄入量继续低于WT小鼠。这些结果暗示α-味蛋白和Trpm 5作为多糖味道的介质，而Trpm 5在脂肪味道中。在Gust KO小鼠中，多糖而不是淀粉偏好的破坏表明不同的感觉信号传导途径介导了对这些碳水化合物的反应。KO小鼠中脂肪和多糖偏好的经验诱导的拯救可能反映了在α-味蛋白和Trpm 5不存在下起作用的后调节机制的作用。
Trpm5 and alpha-gustducin are key to the transduction of tastes of sugars, amino acids, and bitter compounds. This study investigated the role of these signaling proteins in the preference for fat, starch, and starch-derived polysaccharides (Polycose), using Trpm5 knockout (Trpm5 KO) and alpha-gustducin knockout (Gust KO) mice. In initial two-bottle tests (24 h/day), Trpm5 KO mice showed no preference for soybean oil emulsions (0.313-2.5%), Polycose solutions (0.5-4%), or starch suspensions (0.5-4%). Gust KO mice displayed an attenuated preference for Polycose, but their preferences for soybean oil and starch were comparable to those of C57BL/6J wild-type (WT) mice. Gust KO mice preferred starch to Polycose, whereas WT mice had the opposite preference. After extensive experience with soybean oil emulsions (Intralipid) and Polycose solutions, the Trpm5 KO mice developed preferences comparable to the WT mice, although their absolute intakes remained suppressed. Similarly, Gust KO mice developed a strong Polycose preference with experience, but they continued to consume less than the WT mice. These results implicate alpha-gustducin and Trpm5 as mediators of polysaccharide taste and Trpm5 in fat taste. The disruption in Polycose, but not starch, preference in Gust KO mice indicates that distinct, sensory signaling pathways mediate the response to these carbohydrates. The experience-induced rescue of fat and Polycose preferences in the KO mice likely reflects the action of a postoral-conditioning mechanism, which functions in the absence of a-gustducin and Trpm5.