In the past, taste interactions between sodium chloride (NaCl) and bitter tastants were investigated in human sensory studies, and the suppression of bitterness by sodium was observed. It is currently not clear if this phenomenon occurs predominantly peripherally or centrally and if the effect is general or only particular bitter compounds are blocked. Therefore, the influence of NaCl at the receptor level was tested by functional expression assays using four out of ∼25 human bitter taste receptors together with prototypical agonists. It was observed that NaCl affected only the responses of particular bitter taste receptor-compound pairs, whereas other bitter responses remained unchanged upon variations of the sodium concentrations. Among the tested receptors, TAS2R16 showed a reduction in signaling in the presence of NaCl. This demonstrates that for some receptor-agonist pairs, NaCl reduces the activation at the receptor level, whereas central effects may dominate the NaCl-induced bitter taste inhibition for other substances.

中文翻译：

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氯化钠对人类苦味受体反应的影响

过去，在人类感官研究中研究了氯化钠（NaCl）和促苦味剂之间的味觉相互作用，并观察到钠对苦味的抑制作用。目前尚不清楚这种现象主要发生在外周还是中枢，以及效果是普遍的还是仅特定的苦味化合物被阻断。因此，使用约 25 个人类苦味受体中的 4 个以及原型激动剂，通过功能表达测定来测试 NaCl 对受体水平的影响。据观察，氯化钠仅影响特定苦味受体-化合物对的反应，而其他苦味反应在钠浓度变化时保持不变。在测试的受体中，TAS2R16 在 NaCl 存在下表现出信号传导减少。这表明，对于某些受体-激动剂对，氯化钠降低了受体水平的激活，而中枢效应可能主导氯化钠诱导的其他物质的苦味抑制。