Taste sensitivities to PROP and PTC vary independently in mice.
Taste sensitivities to PROP and PTC vary independently in mice.
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DOI：
10.1093/chemse/bjg062
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发表时间：
2003-10
期刊：
影响因子：
3.5
通讯作者：
Theodore M. Nelson;S. Munger;J. Boughter
中科院分区：
文献类型：
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作者：
Theodore M. Nelson;S. Munger;J. Boughter
哺乳动物使用常见的机制来检测、转换和处理味觉刺激信息。例如，它们共享对氨基酸、甜味和苦味刺激做出反应的受体家族。尽管如此，同样清楚的是，不同的物种表现出独特的味觉敏感性，这可能反映了特定的遗传变异。在人类中，对化学性质相似、苦味化合物 6-正丙基硫氧嘧啶 (PROP) 和苯硫脲 (PTC) 的敏感性是可遗传的且密切相关，这表明存在共同的遗传基础。然而，尚不清楚小鼠中 PROP 和 PTC 味觉敏感性是否具有类似的相关性。在这里，我们报告说，两种近交系小鼠的 PROP 和 PTC 味觉敏感性独立变化。在简短的味觉测试中，C3HeB/FeJ (C3) 和 SWR/J (SW) 小鼠对 PTC 具有相似的味觉敏感性，而 SW 小鼠对 PROP 的敏感性明显高于 C3 小鼠。然而，在双瓶偏好测试中，SW 小鼠对这两种化合物表现出更大的厌恶。这种差异可以通过以下观察结果来解释：SW 小鼠在摄入测试期间比 C3 小鼠消耗味觉溶液的速率更高。因此，PTC 回避与摄入测试中消耗的 PTC 量相关，而不是与测试的 PTC 浓度相关。这些发现表明，摄入后因素在摄入测试期间避免 PTC 方面发挥着重要作用，并强调了短暂接触测试相对于摄入测试在解决味觉和摄入后对味觉相关行为的影响方面的重要优势。最引人注目的是，这些结果表明，与人类不同，在小鼠中，PTC 和 PROP 味觉敏感性独立变化，从而表明哺乳动物物种之间的苦味机制存在微妙的功能多样性。
Mammals use common mechanisms to detect, transduce and process taste stimulus information. For example, they share families of receptors that respond to amino acids, and sweet- and bitter-tasting stimuli. Nonetheless, it also clear that different species exhibit unique taste sensitivities that may reflect specific genetic variations. In humans, sensitivities to the chemically similar, bitter-tasting compounds 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC) are heritable and strongly correlated, suggesting a common genetic basis. However, it is unknown whether PROP and PTC taste sensitivities are similarly correlated in mice. Here we report that PROP and PTC taste sensitivities vary independently between two inbred strains of mice. In brief-access taste tests C3HeB/FeJ (C3) and SWR/J (SW) mice possess similar taste sensitivity to PTC, while SW mice are significantly more sensitive to PROP than are C3 mice. In two-bottle preference tests, however, SW mice display greater aversion to both compounds. This discrepancy may be explained by the observation that SW mice consumed taste solutions at a greater rate during the intake test than did C3 mice. Therefore, PTC avoidance is correlated with the amount of PTC consumed in the intake tests rather than the concentration of PTC tested. These findings suggest that post-ingestive factors play a significant role in PTC avoidance during intake tests and highlight an important advantage of brief-access tests over intake tests in resolving the gustatory and post-ingestive contributions to taste-related behaviors. Most strikingly, these results demonstrate that in mice, unlike in humans, PTC and PROP taste sensitivities vary independently, thereby suggesting a subtle functional diversity of bitter-taste mechanisms across mammalian species.