OBJECTIVES/HYPOTHESIS The purpose of this study was to validate the use of edible taste strips for measuring taste recognition thresholds for the bitter-tasting compound 6-n-propylthiouracil (PROP). STUDY DESIGN Taste recognition thresholds for PROP were obtained by two separate methods. Thresholds were also identified in subjects whose airflow through the nose was blocked. Threshold values w...

Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on sour taste of equimolar protonated organic acid solutions and to investigate the potential roles...

The administration of thiol-containing drugs decreases taste acuity in man and animals. Copper (II) and zine (II) administration returns taste acuity to normal levels. The results suggest that (1) thiols and metals are in dynamic equilibrium in the metabolic net, (2) regulation of taste acuity occurs through changes which thiols and/or metals bring about in the conformation of a protein which l...

Taste sensitivity to Phenyl-thio-Carbamide (PTC) and glucose were studied in 150 females during the 3 trimesters of their pregnancy periods. The taste sensitivity to PTC was determined by Harris and Kalmus method. For taste intensity and hedonic evaluation, 7 concentrations of glucose solutions were used. Taste sensitivity to both PTC and glucose increases during the 1st trimester of pregnancy....

Taste buds are clusters of polarized sensory cells embedded in stratified oral epithelium. In adult mammals, taste buds turn over continuously and are replenished through the birth of new cells in the basal layer of the surrounding non-sensory epithelium. The half-life of cells in mammalian taste buds has been estimated as 8-12 days on average. Yet, earlier studies did not address whether the n...

ATP and serotonin (5-HT) are neurotransmitters secreted from taste bud receptor (type II) and presynaptic (type III) cells, respectively. Norepinephrine (NE) has also been proposed to be a neurotransmitter or paracrine hormone in taste buds. Yet, to date, the specific stimulus for NE release in taste buds is not well understood, and the identity of the taste cells that secrete NE is not known. ...

Sections of tissues containing lingual and extra-lingual taste buds were evaluated with monoclonal antibodies against cytokeratins. In the caudal third of the rat's tongue, keratin 20 immunoreactivity was restricted to taste buds, whereas keratins 7, 8, 18, and 19 were expressed in vallate and foliate taste buds and in cells of salivary ducts that merge with these taste epithelia. Hence, antibo...

The acid-sensitive cation channel acid-sensing ion channel-2 (ASIC2) is widely believed to be a receptor for acid (sour) taste in mammals on the basis of its physiological properties and expression in rat taste bud cells. Using reverse transcriptase-PCR, we detected expression of ASIC1 and ASIC3, but not ASIC4, in mouse and rat taste buds and nonsensory lingual epithelium. Surprisingly, we did ...

Functional Near-Infrared Spectroscopy (fNIRS), as a non-invasive neuroimaging technique, was used to monitor the activation of prefrontal lobe on human brain during sweet taste processing. The primary aim of the present study was to find the region of interest (ROI) which is related to sweetness, and make further understanding of the central organization of taste. Based on event-related design,...