Rapid kinetics of second messenger production in bitter taste

作者：Andrew Spielman, H. Nagai, Gulshan Sunavala, Marina Ercilia Dasso, Heinz Breer, Ingrid Boekhoff, Taufiqul Huque, Glayde Whitney, Joseph G. Brand · 发表于：American Journal of Physiology-Cell Physiology · 年份：1996 · DOI：10.1152/ajpcell.1996.270.3.c926 · 被引用次数：92 · 研究领域：Biochemical Analysis and Sensing Techniques、Olfactory and Sensory Function Studies、Advanced Chemical Sensor Technologies

The tasting of bitter compounds may have evolved as a protective mechanism against ingestion of potentially harmful substances. We have identified second messengers involved in bitter taste and show here for the first time that they are rapid and transient. Using a quench-flow system, we have studied bitter taste signal transduction in a pair of mouse strains that differ in their ability to taste the bitter stimulus sucrose octaacetate (SOA); however, both strains taste the bitter agent denatonium. In both strains of mice, denatonium (10 mM) induced a transient and rapid increase in levels of the second messenger inositol 1,4,5-trisphosphate (IP3) with a maximal production near 75-100 ms after stimulation. In contrast, SOA (100 microM) brought about a similar increase in IP3 only in SOA-taster mice. The response to SOA was potentiated in the presence of GTP (1 microM). The GTP-enhanced SOA-response supports a G protein-mediated response for this bitter compound. The rapid kinetics, transient nature, and specificity of the bitter taste stimulus-induced IP3 formation are consistent with the role of IP3 as a second messenger in the chemoelectrical transduction of bitter taste.