Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0235290 (bitter taste)
 1,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electrical responses of ventromedial (VMH) and lateral (LH) hypothalamus to graded decrease in body weight and to taste were recorded from a conscious rat with chronically implanted macroelectrodes. Graded reduction in body weight was correlated with gradual increase in LH activity and reciprocal decrease in VMH activity, both of which were stable and specific to each gradation in body weight. On gustation of any test solution, basal activity was temporarily altered, if any. On sweet taste of calorically rich sucrose, VMH activity was enhanced and LH showed decrease. But on sweet taste of calorically inert saccharin, VMH activity was increased, though a reciprocal decrease in LH was not shown. Contrastingly, both bitter taste and salt taste caused increased LH activity but no change in VMH activity. Enhanced VMH activity correlated with sweet taste may be due to activation of VMH glucoreceptors. LH activation correlated with bitter and salt taste is a likely response of two distinct groups of LH units; one responding to salt taste and the other to bitter aversive taste.
 ...
PMID:Effects of body weight loss and taste on VMH-LH electrical activity of rats. 148 78

The application of new techniques to the study of taste cells has revealed much about both the basic physiology of these cells and also about the mechanisms of taste transduction. The taste cells are electrically excitable cells with a variety of voltage-dependent ion currents. These ionic currents have an important role in the transduction of salt taste in mammals and frogs. In mudpuppies different ion channels are involved in the transduction of acidic-sour stimuli. The role of ion currents in the transduction of sweet taste is less clear. Some proposed mechanisms suggest an important role for ion currents and others suggest that the transduction process may be a biochemical event involving cell surface receptors and intracellular second messengers, possibly cAMP. The transduction of bitter taste seems to be a biochemical event involving cell surface receptors and intracellular second messengers in the inositol trisphosphate pathway. Thus, one cannot talk about "the mechanism" of taste transduction. Different taste modalities are transduced by different mechanisms. A corollary to this is that taste cells are not a homogeneous population of cells. In order to provide animals with the ability to discriminate between different taste modalities the taste cells consist of distinct subpopulations of cells based on their primary taste modality. The primary taste modality in a given cell is determined by the receptors and transduction mechanism(s) expressed in that cell. Evidence suggests that modality-specific receptors are expressed in a segregated manner in distinct subpopulations of taste cells. Secondary responses observed in gustatory axons may arise due to a lack of absolute specificity in the transduction processes and nonspecific effects of low pH and high ionic strength and osmolarity on the taste cells. An interesting area for future work will be to elucidate the mechanism(s) by which basal cells become committed to a given taste modality and how the gustatory neurons influence this process of differentiation. The involvement of the gustatory neurons is critical as they must synapse with taste cells of the correct taste modality to preserve the integrity of the information transferred to the CNS. This process of synaptogenesis is presumably mediated by the expression of taste-modality-specific, cell surface antigens on the basolateral domain of a taste cell and receptors on the appropriate neurons, but much work will be necessary to elucidate this process.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Mechanisms of chemosensory transduction in taste cells. 170 88

Recognition thresholds for the four basic tastes (salt, sour, sweet and bitter) were tested by the forced-choice technique in 27 patients with small-cell lung cancer, and 22 weight-matched control patients with non-malignant diseases. No significant differences in threshold concentrations could be demonstrated. When patients who were losing weight were compared with weight-stable patients, significantly lower taste thresholds for bitter substances were found in weight losing groups in both cancer and control patients. Small-cell lung cancer patients who responded to therapy had obtained an increased threshold for bitter taste at the time of reevaluation than at the time of diagnosis, an effect that may be explained by the chemotherapeutic regimen. The results suggest that in patients with small-cell lung cancer it is not the cancer disease per se but the weight loss that often accompanies it that causes an increased taste sensitivity for bitter substances.
 ...
PMID:Taste thresholds in patients with small-cell lung cancer. 184 1

Gustatory differences in Phenylthiocarbamide (PTC) tasters and non-tasters were studied in hypothyroid and hyperthyroid subjects. After presenting for PTC sensitivity, gustatory responses to 7 dilutions of test solutions for glucose (sweet), sodium chloride (salt), citric acid (sour) and quinine sulphate (bitter) were studied in PTC tasters and non-tasters. The intensity and pleasantness responses for 4 basic tastes were measured on a 7-point and 6-point category scale respectively. Sixty percent of subjects of hyperthyroid and 40% of hypothyroid subjects were tasters. Hypothyroid subjects showed more gustatory differences as compared to hyperthyroids. The diminished intensity perception for sweet and bitter taste was much more prominent in non-tasters than tasters hypothyroids. The greater hedonic value for salt was largely observed among hypothyroid tasters.
 ...
PMID:Gustatory differences in hypothyroid and hyperthyroid tasters and non-tasters. 228 24

Spices were selected for study that were believed to exhibit properties related to the sweetness commonly found in foods and beverages. Seventy healthy, normal-weight adults first smelled and then tasted 10 spices. Subjects responded to two questionnaires, judging similarity of the spices and indicating the sensory attributes important in their decision making. Intensity of odor, compatibility with sweetness, and degree of bitter taste were three major attributes used to arrive at similarity judgments. Overall, vanilla was found to be most similar to sugar. When examined further for compatibility with sweetness, cinnamon, vanilla, spearmint, and anise were generally found to be more comparable to sugar than nutmeg, ginger, cloves, bay, and salt. Nonwhite subjects, as opposed to white subjects, attributed greater sweetness to nutmeg and less sweetness to anise. The data suggest that certain spices exhibit sweet properties and may provide a healthful strategy for reducing sugar intake.
 ...
PMID:Sugar and spice: similarities and sensory attributes. 239 34

Effects of body weight (bw) decrease induced by restruction of food intake by 75%, 50% and 25% on responses to 1-hr single bottle gustatory tests with glucose, saccharin, salt and quinine were investigated. Rats fed ad libitum served as controls. Food-restricted rats showed dynamic and static loss of bw, the rate and magnitude being proportional to food intake. With the increase in static bw loss across groups, intake on sweet and salt taste was increased and on bitter taste decreased as compared to controls. Though on rapid dynamic bw loss, progressive increase on sweet and salt taste, and gradual decrease on bitter taste was seen with duration of adaptation, it was not commensurate with magnitude of bw loss. However, on slow loss of bw, taste based intake was proportional to bw loss.
 ...
PMID:Effects of dynamic and static body weight loss on taste responses. 685 84

A zinc-containing salt of theophylline, Zn(II)-aminophylline, was synthesized and its structure determined by X-ray diffraction techniques. The zinc ion is coordinated to two theophylline anions and a molecule of ethylenediamine in a tetrahedral arrangement. The solubility of the compound in water at 30 degrees (0.047 mg/ml) is 180-fold lower than that of theophylline (8.40 mg/ml). The complex is relatively stable in the alkaline pH range, but it hydrolyzes, releasing theophylline in acidic environments. The rate of theophylline release is pH dependent. These properties are useful in formulating chewable tablets and liquid suspension dosage forms that overcome the characteristic bitter taste of theophylline, yet provide for efficacious treatment of diseases involving the respiratory tract.
 ...
PMID:Zn(II)-theophylline-ethylenediamine: structure and pH stability. 686 69

The development of a specific inhibitor for bitter taste has been widely required in the fields of taste physiology and pharmaceutical sciences, but no inhibitor has been available. We found that lipoproteins, PA-LG composed of phosphatidic acid (PA) and beta-lactoglobulin (LG) and PA-LA composed of PA and alpha-lactalbumin (LA) reversibly suppressed the responses of the frog glossopharyngeal nerve to the bitter substances. The frog tongue was treated with PA-LG solution for 10 min and then stimulated by a stimulus dissolved in water. The responses to the bitter substances such as quinine hydrochloride, papaverine hydrochloride, caffeine and L-leucine were completely suppressed by PA-LG, while those to the salt type bitter substances such as CsCl, MgCl2 and tetraethylammonium chloride were not suppressed. The responses to NaCl, galactose, acetic acid and L-alanine were unchanged or only slightly increased. The results suggested that binding of PA-LG to the hydrophobic region of the receptor membranes leads to suppression of the responses to the bitter substances. It was pointed out that PA-LG is useful not only for elucidating the receptor mechanisms of bitter substances, but also can be safely used to mask the bitter taste of foods and drugs, since PA, LG and LA are prepared from foods (soybean and milk).
 ...
PMID:Lipoprotein that selectively inhibits taste nerve responses to bitter substances. 872 96

The delivery of sumatriptan doses intranasally could add greater flexibility in the treatment of migraine than is possible with the currently available subcutaneous and oral sumatriptan preparations. Two independent double-blind, randomized, placebo-controlled clinical studies were conducted to evaluate the safety, tolerability and pharmacokinetics of intranasally administered sumatriptan following ascending single doses (three different dose levels) and multiple doses. In the four-way, crossover, ascending-dose study, 20 healthy female subjects were randomized to receive on separate occasions single intranasal spray doses of 5, 10, or 20 mg sumatriptan (as the hemisulphate salt) or placebo into one nostril. Adverse events were mild and consisted mainly of bitter taste at the back of the throat and events typical of sumatriptan administered by other routes (headache, lightheadedness and tingling). Area under the plasma sumatriptan concentration versus time curve (AUC infinity) and peak plasma concentration (Cmax) increased with the dose. Dose proportionality was demonstrated between 5 and 10 mg but not across the dose range 5-20 mg. Time to maximum plasma concentration (tmax) was variable due to multiple peaking. The elimination half-life (t1/2), approximately 2 h, was unaffected by the magnitude of dose. In the two-period, multiple-dose, crossover study, 12 healthy adult male and female subjects were randomized to receive either sumatriptan hemisulphate 20 mg or placebo, administered intranasally as a spray three times a day for 4 days. The two dosing periods were separated by 3 to 14 days. Multiple doses of sumatriptan were well tolerated, with no serious adverse events occurring or withdrawals due to adverse events. All patients reported a mild to moderate drug-related disturbance of taste. Nasal examinations remained normal, and olfactory function was unaffected. The AUC over the first 8 h following dosing (AUC8) and fraction of the dose excreted in the urine (fe; 6.2% vs 3.6%) were similar on Days 1 and 4. Day 4 values were significantly higher (p < or = 0.05) for Cmax (16.9 ng/ml vs 13.1 ng/ml), renal clearance (Clr; 19.0 l/h vs 14.2 l/h), and t1/2 (2.18 h vs 1.93 h), and shorter for tmax (0.88 h vs 1.75 h). Some accumulation (22%) occurred over the 4 days of dosing. Serum concentrations of the pharmacologically inactive indole acetic acid metabolite of sumatriptan were fourfold to fivefold higher than corresponding sumatriptan concentrations. Overall, these studies show that the sumatriptan intranasal spray formulation is well tolerated, allows rapid absorption of sumatriptan, and results in only a clinically insignificant degree of sumatriptan accumulation upon repeated dosing.
 ...
PMID:Safety, tolerability, and pharmacokinetics of sumatriptan in healthy subjects following ascending single intranasal doses and multiple intranasal doses. 920 76

The chorda tympani nerve (CT) mediates taste from the anterior part of the tongue. Here we studied the effects of ethanol on the tongue in recordings from both the whole CT nerve and individual taste fibers of the rhesus monkey, M. mulatta. The response to ethanol consisted of a phasic and a tonic part. At the lowest concentration tested (0.3 M) ethanol gave a response in some animals and at 0.7 M in all animals. A sigmoidal function described best the relationship between nerve response and ethanol concentrations. Hierarchial cluster analysis with 26 nonalcoholic sweet, sour, salty, and bitter stimuli had earlier identified four types of taste fibers each responding predominantly to stimuli within one of the four human taste qualities. Here were found that ethanol stimulated all sweet-best fibers and at high concentration some salt-best fibers, but never any acid-best and bitter-best fibers. This may explain the sweet taste attributed to low ethanol concentration by humans. Further, in mixtures it suppressed the responses in acid-best and bitter-best taste fibers. This may partly explain the effects of ethanol on sour and bitter taste in alcoholic beverages.
 ...
PMID:The taste of ethanol in a primate model: I. Chorda tympani nerve response in Macaca mulatta. 930 63


1 2 3 4 5 6 Next >>