Localization of phosphatidylinositol signaling components in rat taste cells: role in bitter taste transduction.
To assess the role of phosphatidylinositol turnover in taste transduction we have visualized, in rat tongue, ATP-dependent endoplasmic reticular accumulation of 45Ca2+, inositol 1,4,5-trisphosphate receptor binding sites, and phosphatidylinositol turnover monitored by autoradiography of [3H]cytidine diphosphate diacylglycerol formed from [3H]cytidine. Accumulated 45Ca2+, inositol 1,4,5-trisphosphate receptors, and phosphatidylinositol turnover are selectively localized to apical areas of the taste buds of circumvallate papillae, which are associated with bitter taste. Further evidence for a role of phosphatidylinositol turnover in bitter taste is our observation of a rapid, selective increase in mass levels of inositol 1,4,5-trisphosphate elicited by low concentrations of denatonium, a potently bitter tastant.
Hwang
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PM
Johns Hopkins University School of Medicine, Department of Neuroscience, Baltimore, MD 21205.
Verma
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Bredt
D S
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Snyder
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SH
D000818:Animals; D001345:Autoradiography; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D002217:Carbachol / Q000494:pharmacology; D004848:Epithelium / Q000502:physiology; D008297:Male; D010716:Phosphatidylinositols / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011984:Sensory Receptor Cells / Q000502:physiology*; D015398:Signal Transduction; D013649:Taste; D013650:Taste Buds / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D014316:Tritium
D002132:Calcium Radioisotopes; D010716:Phosphatidylinositols; D014316:Tritium; D002217:Carbachol; D002118:Calcium