Enhanced responses of the chorda tympani nerve to nonsugar sweeteners in the diabetic db/db mouse.
Genetically diabetic db/db mice show greater neural and behavioral responses to sugars than lean control mice. The present study examined chorda tympani responses of db/db mice to nonsugar sweeteners and their inhibition by a sweet response inhibitor, gurmarin. The results showed that responses to sucrose, saccharin, glycine, L-alanine, and D-tryptophan, but not to D-phenylalanine, were approximately 1.5 times greater in db/db mice than in control mice. Treatment of the tongue with gurmarin suppressed responses to these sweeteners in db/db and control mice, but the extent of suppression was considerably smaller in db/db mice. The magnitudes of gurmarin-sensitive components of the response to sweeteners in db/db mice were not significantly different from those in control mice, whereas the magnitudes of gurmarin-insensitive components in db/db mice were about twice as large as those in control mice. These results suggest that the enhancement of chorda tympani responses in db/db mice to sucrose and other nonsugar sweeteners may occur through gurmarin-insensitive membrane components.
Ninomiya
Y
Y
Department of Oral Physiology, Chemistry and Pediatric Dentistry, Asahi University School of Dentistry, Gifu, Japan.
Imoto
T
T
Yatabe
A
A
Kawamura
S
S
Nakashima
K
K
Katsukawa
H
H
D000818:Animals; D002814:Chorda Tympani Nerve / Q000187:drug effects* / Q000502:physiology*; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D008297:Male; D051379:Mice; D010940:Plant Proteins / Q000008:administration & dosage*; D013549:Sweetening Agents / Q000008:administration & dosage*; D013650:Taste Buds / Q000502:physiology
D010940:Plant Proteins; D013549:Sweetening Agents; C075206:Gurmarin protein, Gymnema sylvestre