Taste functions

In many cells, phosphoinositide signaling leads to an elevation in intracellular calcium levels through the release of calcium from intracellular stores in response to IP3-dependent gating of channels in the endoplasmic epithelium (Ch. 20). It is not known if IP3 plays a critical role in TRC transduction, but such a role would be consistent with recent findings that a Ca2+-activated cation channel, TRPM5, is essential for normal sweet, bitter and umami taste function [49,66-69],... 

SAFETY PROFILE Poison by intraperitoneal and intravenous routes. Moderately toxic by ingestion and subcutaneous routes. Human systemic effects change in taste function. An experimental teratogen. Experimental reproductive effects. Mutation data reported. When heated to decomposition it emits very toxic fumes of HCl and NOx. See also TETRACYCLINE. 

Many excellent reviews have been published in the last few years covering different aspects of sweet taste function (Bachmanov and Beauchamp 2007 Boughter and Bachmanov 2007 Chandrashekar et al. 2006 Lemon and Katz 2007 Roper... 

Shimura T, Watanabe U, Yanagawa Y, Yamamoto T (2004) Altered taste function in mice deficient in the 65-kDa isoform of glutamate decarboxylase. Neurosd Lett 356 171-174. 

Overall, it is clear from the present review that much more research is needed to explore cross-cultural differences in smell and taste function. Furthermore, it is apparent that the reasons for cultural differences, when present, can be quite complex. In addition to the factors mentioned above, it should be noted, in closing, that variations in the general health and nutrition of subjects may also account for some cross-cultural differences in smell and taste function. Thus, persons on sodium restricted diets come to prefer low concentrations of salt (Bertino et al., 1982), and taste preferences for sucrose can be altered by the actions of insulin (Jacobs, 1958 Mayer-Gross and Walker, 1956). As dramatically pointed out by Lepkovsky (1977), American soldiers in a World War II prison camp, who were subsisting on a ration which was 200 calories short of their basal needs, developed food preferences which differed considerably from those exhibited under normal conditions. Thus, powdered milk became the most preferred item, followed by meat. Cheese, jam, sugar and chocolate bars were not strongly preferred. 

Carbohydrates are polyhydroxylaldehydes or ketones or compounds which produce them on hydrolysis. The name carbohydrate means hydrates of carbon . The term sugar is used for those carbohydrates which are water soluble and sweet to taste.Functions ... 

The aroma of fmit, the taste of candy, and the texture of bread are examples of flavor perception. In each case, physical and chemical stmctures ia these foods stimulate receptors ia the nose and mouth. Impulses from these receptors are then processed iato perceptions of flavor by the brain. Attention, emotion, memory, cognition, and other brain functions combine with these perceptions to cause behavior, eg, a sense of pleasure, a memory, an idea, a fantasy, a purchase. These are psychological processes and as such have all the complexities of the human mind. Flavor characterization attempts to define what causes flavor and to determine if human response to flavor can be predicted. The ways ia which simple flavor active substances, flavorants, produce perceptions are described both ia terms of the physiology, ie, transduction, and psychophysics, ie, dose-response relationships, of flavor (1,2). Progress has been made ia understanding how perceptions of simple flavorants are processed iato hedonic behavior, ie, degree of liking, or concept formation, eg, crispy or umami (savory) (3,4). However, it is unclear how complex mixtures of flavorants are perceived or what behavior they cause. Flavor characterization involves the chemical measurement of iadividual flavorants and the use of sensory tests to determine their impact on behavior. 

Only acids are sour. Sourness is not identical to chemical acidity or pH, which is a function of the hydrogen ion concentration, but also appears to be a function of the entire acid molecule. A combination of pH and acid concentration determines the actual degree of the sour taste. At the same pH, any organic acid, eg, citric acid, exhibits a far greater sourness than a mineral acid, eg, hydrochloric acid (27,28). 

Penicillamine (29) can be effective in patients with refractory RA and may delay progression of erosions, but adverse effects limit its useflilness. The most common adverse side effects for penicillamine are similar to those of parenteral gold therapy, ie, pmritic rash, protein uria, leukopenia, and thrombocytopenia. Decreased or altered taste sensation is a relatively common adverse effect for penicillamine. A monthly blood count, platelet count, and urinalysis are recommended, and also hepatic and renal function should be periodically monitored. Penicillamine is teratogenic and should not be used during pregnancy. 

Pharmaceutical Applications. Sucrose has a long history in the manufacture of pharmaceuticals. It imparts body to symps and medicinal hquids and masks unpleasant tastes. Sucrose also functions as a diluent to control dmg concentrations in medicines, as an ingredient binder for tablets, and to impart chewiness to the latter. Sustained-release medications and protective tablet glazes are prepared using sucrose (41). Sucrose-based sugar pastes are used to promote wound healing (58). 

Some proteins display rather exotic functions that do not quite fit the previous classifications. Monellin, a protein found in an African plant, has a very sweet taste and is being considered as an artificial sweetener for human consumption. Resilin, a protein having exceptional elastic properties, is found in... 

More than half of the patients receiving this drug by the parenteral route experience some adverse reaction. Severe and sometimes life-threatening reactions include leukopenia (low white blood cell count), hypoglycemia (low blood sugar), thrombocytopenia (low platelet count), and hypotension (low blood pressure). Moderate or less severe reactions include changes in some laboratory tests, such as the serum creatinine and liver function tests. Other adverse reactions include anxiety, headache, hypotension, chills, nausea, and anorexia Aerosol administration may result in fatigue a metallic taste in the mouth, shortness of breath, and anorexia... 

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