Abstract
It is known that L-γ-Glutamyl-L-cysyeinylglycine (GSH), a tripeptide with glutamic acid, cysteine and glycine, increases flavor characteristics of an umami solution containing each of monosodium glutamate (MSG) and 5-inosine monophosphate (IMP) in human (Ueda et al., 1997). In this study, we conducted behavioral and electorophysiological experiments to investigate the neurophysiological characteristics of GSH for the taste receptor by using C57BL/6 mice. In the behavioral study, preference percent for IMP mixed with GSH was higher than that for pure IMP. But mixing of GSH did not change the preference percents for MPG and binary mixture of MPG and IMP. In the electrophysiological study, when GSH was mixed with IMP, the chorda tympani nerve response showed strong synergistic effect. But mixing of GSH did not increase the response to MPG. The response of mixture of MPG and IMP was cross-adapted by that of GSH + IMP in the chorda tympani nerve. It is possible that GSH attacks the site for glutamate and make synergistic effect with IMP. [J Physiol Sci. 2007;57 Suppl:S108]
