The capsaicin receptor participates in artificial sweetener aversion.
Artificial sweeteners such as saccharin, aspartame, acesulfame-K, and cyclamate produce at high concentrations an unpleasant after-taste that is generally attributed to bitter and metallic taste sensations. To identify receptors involved with the complex perception of the above compounds, preference tests were performed in wild-type mice and mice lacking the TRPV1 channel or the T1R3 receptor, the latter being necessary for the perception of sweet taste. The sweeteners, including cyclamate, displayed a biphasic response profile, with the T1R3 mediated component implicated in preference. At high concentrations imparting off-taste, omission of TRPV1 reduced aversion. In a heterologous expression system the Y511A point mutation in the vanilloid pocket of TRPV1 did not affect saccharin and aspartame responses but abolished cyclamate and acesulfame-K activities. The results rationalize artificial sweetener tastes and off-tastes by showing that at low concentrations, these molecules stimulate the gustatory system through the hedonically positive T1R3 pathway, and at higher concentrations, their aversion is partly mediated by TRPV1.
Riera
Céline E
CE
Nestlé Research Center, Vers-chez-les-Blanc, Perception Physiology, PO Box 44, CH-1000 Lausanne 26, Switzerland.
Vogel
Horst
H
Simon
Sidney A
SA
Damak
Sami
S
le Coutre
Johannes
J
D000818:Animals; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D043562:Receptors, G-Protein-Coupled / Q000819:agonists / Q000235:genetics / Q000502:physiology*; D013549:Sweetening Agents / Q000378:metabolism* / Q000494:pharmacology; D050916:TRPV Cation Channels / Q000819:agonists / Q000235:genetics / Q000502:physiology*; D013649:Taste / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
D043562:Receptors, G-Protein-Coupled; D013549:Sweetening Agents; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; C431926:taste receptors, type 1