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Am J Physiol Regul Integr Comp Physiol. 2009 Apr;296(4):R866-76. doi: 10.1152/ajpregu.90870.2008. Epub 2008 Dec 17.

T1R3 taste receptor is critical for sucrose but not Polycose taste.

Author information

1
Dept. of Psychology, Brooklyn College of CUNY, Brooklyn, NY 11210, USA.

Abstract

In addition to their well-known preference for sugars, mice and rats avidly consume starch-derived glucose polymers (e.g., Polycose). T1R3 is a component of the mammalian sweet taste receptor that mediates the preference for sugars and artificial sweeteners in mammals. We examined the role of the T1R3 receptor in the ingestive response of mice to Polycose and sucrose. In 60-s two-bottle tests, knockout (KO) mice preferred Polycose solutions (4-32%) to water, although their overall preference was lower than WT mice (82% vs. 94%). KO mice also preferred Polycose (0.5-32%) in 24-h two-bottle tests, although less so than WT mice at dilute concentrations (0.5-4%). In contrast, KO mice failed to prefer sucrose to water in 60-s tests. In 24-h tests, KO mice were indifferent to 0.5-8% sucrose, but preferred 16-32% sucrose; this latter result may reflect the post-oral effects of sucrose. Overall sucrose preference and intake were substantially less in KO mice than WT mice. However, when retested with 0.5-32% sucrose solutions, the KO mice preferred all sucrose concentrations, although they drank less sugar than WT mice. The experience-induced sucrose preference is attributed to a post-oral conditioned preference for the T1R3-independent orosensory features of the sugar solutions (odor, texture, T1R2-mediated taste). Chorda tympani nerve recordings revealed virtually no response to sucrose in KO mice, but a near-normal response to Polycose. These results indicate that the T1R3 receptor plays a critical role in the taste-mediated response to sucrose but not Polycose.

PMID:
19091911
PMCID:
PMC2698610
DOI:
10.1152/ajpregu.90870.2008
[Indexed for MEDLINE]
Free PMC Article

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