title: Mouse strain differences in Gurmarin-sensitivity of sweet taste responses are not associated with polymorphisms of the sweet receptor gene, Tas1r3.
abstract: Gurmarin (Gur) is a peptide that selectively inhibits responses of the chorda tympani (CT) nerve to sweet compounds in rodents. In mice, the sweet-suppressing effect of Gur differs among strains. The inhibitory effect of Gur is clearly observed in C57BL/6 mice, but only slightly, if at all, in BALB/c mice. These two mouse strains possess different alleles of the sweet receptor gene, Sac (Tas1r3) (taster genotype for C57BL/6 and non-taster genotype for BALB/c mice), suggesting that polymorphisms in the gene may account for differential sensitivity to Gur. To investigate this possibility, we examined the effect of Gur in another Tas1r3 non-taster strain, 129 X 1/Sv mice. The results indicated that unlike non-taster BALB/c mice but similar to taster C57BL/6 mice, 129 X 1/Sv mice exhibited significant inhibition of CT responses to various sweet compounds by Gur. This suggests that the mouse strain difference in the Gur inhibition of sweet responses of the CT nerve may not be associated with polymorphisms of Tas1r3.
authors.affiliation: Section of Oral Neuroscience, Graduate School of Dental Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sanematsu
authors.forename: Keiko
authors.initials: K
authors.lastname: Yasumatsu
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Yoshida
authors.forename: Noriatsu
authors.initials: N
authors.lastname: Shigemura
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Ninomiya
mesh_terms: D000818:Animals; D002814:Chorda Tympani Nerve / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D010940:Plant Proteins / Q000494:pharmacology*; D011110:Polymorphism, Genetic; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled; D013045:Species Specificity; D013395:Sucrose / Q000494:pharmacology; D013549:Sweetening Agents / Q000494:pharmacology; D013649:Taste / Q000502:physiology*; D013650:Taste Buds / Q000187:drug effects* / Q000502:physiology
chemical_list: D010940:Plant Proteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D013549:Sweetening Agents; C431926:taste receptors, type 1; C075206:Gurmarin protein, Gymnema sylvestre; D013395:Sucrose