Ninomiya Y, Imoto T
Department of Oral Physiology, Asahi University School of Dentistry, Gifu, Japan.
Am J Physiol. 1995 Apr;268(4 Pt 2):R1019-25. doi: 10.1152/ajpregu.1995.268.4.R1019.
The inhibitory effects of gurmarin (a peptide isolated from the leaves of Gymnema sylvestre) on sweet taste responses were studied by examining the chorda tympani nerve responses to various taste substances before and after lingual treatment with gurmarin in C57BL and BALB mice. Treatment with gurmarin at 3 micrograms/ml or more selectively suppressed responses to sucrose without affecting responses to NaCl, HCl, and quinine in C57BL mice, whereas gurmarin at 100 micrograms/ml did not significantly suppress sucrose responses in BALB mice. Responses to various sweet substances in C57BL mice decreased to approximately 45-75% of control after gurmarin, and the suppressive effect of gurmarin was reversible. The profile of the residual responses of C57BL mice to various sweeteners after gurmarin was almost identical to that of BALB mice, which was hardly affected by gurmarin. These results strongly suggest that there are at least two types of sweet taste receptors in mice, gurmarin-sensitive and -insensitive. Probably, C57BL and BALB mice share an identical gurmarin-insensitive receptor, and C57BL mice also have a gurmarin-sensitive receptor.
通过检测C57BL和BALB小鼠在用匙羹藤酸（从匙羹藤叶中分离出的一种肽）进行舌部处理前后鼓索神经对各种味觉物质的反应，研究了匙羹藤酸对甜味反应的抑制作用。在C57BL小鼠中，用3微克/毫升或更高浓度的匙羹藤酸处理可选择性地抑制对蔗糖的反应，而不影响对氯化钠、盐酸和奎宁的反应，而100微克/毫升的匙羹藤酸对BALB小鼠的蔗糖反应没有显著抑制作用。C57BL小鼠在用匙羹藤酸处理后，对各种甜味物质的反应降至对照的约45 - 75%，且匙羹藤酸的抑制作用是可逆的。C57BL小鼠在用匙羹藤酸处理后对各种甜味剂的残余反应谱与几乎不受匙羹藤酸影响的BALB小鼠的反应谱几乎相同。这些结果强烈表明，小鼠中至少存在两种类型的甜味受体，即对匙羹藤酸敏感和不敏感的受体。可能，C57BL和BALB小鼠共享相同的对匙羹藤酸不敏感的受体，并且C57BL小鼠还具有对匙羹藤酸敏感的受体。
