Taurine
Template:Chembox new Taurine or 2-aminoethanesulfonic acid is an organic acid that is abundant in the tissues of many animals (metazoa).[1] Taurine is also found in plants, fungi, and some bacterial species, but at lower levels. Taurine is a derivative of the sulphur-containing (sulfhydryl) amino acid, cysteine.
Taurine is named after the Latin taurus, which means bull, as it was first isolated from red bull (Bos taurus) bile as well as semen in 1827 by Austrian scientists Friedrich Tiedemann and Leopold Gmelin. It is often called an amino acid, even in scientific literature,[2][3][4] but it lacks a carboxyl group and therefore does not qualify as an amino acid.[5] It does contain a sulfonate group and may be called an amino sulfonic acid. Small polypeptides have been identified which contain taurine but to date no aminoacyl tRNA synthetase has been identified as specifically recognizing taurine and capable of charging it onto a tRNA.[6]
Biosynthesis
The major pathway for mammalian taurine synthesis occurs in the liver via the cysteine sulfinic acid pathway. In this pathway, the sulfhydryl group of cysteine is first oxidized to cysteine sulfinic acid by the enzyme cysteine dioxygenase. Cysteine sulfinic acid, in turn, is decarboxylated by Sulfinoalanine decarboxylase (EC 4.1.1.27) to form hypotaurine. It is unclear whether hypotaurine is then spontaneously or enzymatically oxidized to yield taurine.
Taurine in the pharmaceutical and lab setting is synthesized through a combination of cysteine, methionine and vitamin E.
Urban legends surrounding the source of taurine have included bull urine extract and bull semen. While it's true that taurine is found in both sources, it is not the source of taurine in the pharmaceutical or food industry.
Physiological roles
Taurine is conjugated via its amino terminal group with the bile acids chenodeoxycholic acid and cholic acid to form the bile salts sodium taurochenodeoxycholate and sodium taurocholate (see bile). The low pKa (1.5) of taurine's sulfonic acid group ensures that this moiety is negatively charged in the pH ranges normally found in the intestinal tract and thus improves the surfactant properties of the cholic acid conjugate.
Taurine has also been implicated in a wide array of other physiological phenomena including inhibitory neurotransmission, long-term potentiation in the striatum/hippocampus, membrane stabilization, feedback inhibition of neutrophil/macrophage respiratory bursts, adipose tissue regulation, and calcium homeostasis. The evidence for these claims, when compared against that reported for taurine's role in bile acid synthesis and osmoregulation, is relatively poor.
Prematurely born infants who lack the enzymes needed to convert cystathionine to cysteine may become deficient in taurine. Thus, taurine is a dietary essential nutrient in these individuals and is often added to many infant formulas as a measure of prudence. There is also evidence that taurine in adult humans reduces blood pressure.[7]
Anxiety disease/panic disorder also show signs of amelioration.[citation needed] If taurine is going to work, it works almost immediately.[citation needed] Recent studies show that taurine supplements taken by mice on a high-fat diet reduced their overall weight. Studies have yet to be done on the effect of taurine on obesity in humans.[8]. Recent studies have also shown that taurine can influence (and possibly reverse) nerve blood flow, motor nerve conduction velocity, and nerve sensory threshold defects in experimental diabetic neuropathic rats.[9][10] Taurine levels were found to be significantly lower in vegans than in a control group on a standard American diet. Plasma taurine was 78% of control values, and urinary taurine 29%.[11] In recent years, taurine has become a common ingredient in energy drinks. Taurine is also often used in combination with bodybuilding supplements such as creatine and anabolic steroids. Taurine is also used in some contact lens solutions. Taurine has also been shown in diabetic rats to decrease weight and decrease blood sugar.[12]
Taurine and cats
Taurine is essential for cat health, as a cat cannot synthesize the compound. The absence of taurine causes a cat's retina to slowly degenerate, causing eye problems and (eventually) irreversible blindness. This condition is called central retinal degeneration (CRD).[13][14] In addition, taurine deficiency can cause feline dilated cardiomyopathy, and supplementation can reverse left ventricular systolic dysfunction. (Pion et al 1988) Taurine is now a requirement of the AAFCO and any dry or wet food product labeled approved by the AAFCO should have a minimum of .1% Taurine. For further AAFCO requirements for cats, consult the table here.
Safety Data
Usage above 28.57 PPM in non-alcoholic beverages is deemed non-GRAS as determined by Flavor and Extract Manufacturers Association (FEMA) Expert Panel. A typical energy drink that contains 1000 mg of taurine corresponds to a concentration of about 4.083 ppm.
Products containing taurine
Taurine is an ingredient in many energy drinks and energy products; in fact, it is from this ingredient that Red Bull gets its name.[citation needed] It is present in the alcoholic drinks Sparks and Spykes. It is also found as an additive in no-rub contact lens fluids. It is in Foosh Energy Mints and Buzz Bites Chocolate Energy Chews. SoBe Power Fruit Punch contains 50 MG of Taurine, while SoBe Adrenaline Rush contains 960mg.
References
- ^ Brosnan J, Brosnan M (2006). "The sulfur-containing amino acids: an overview". J Nutr. 136 (6 Suppl): 1636S–1640S. PMID 16702333.
- ^ Stapleton, PP (1998). "Host defense--a role for the amino acid taurine?". Journal of Parenteral and Enteral Nutrition. 22 (1): 42–48. Retrieved 2006-08-19.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Weiss, Stephen J. (1982). "Chlorination of Taurine by Human Neutrophils". Journal of Clinical Investigation. 70 (3): 598–607. Retrieved 2006-08-19.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Kirk, Kiaran (1993). "Volume-regulatory taurine release from a human lung cancer cell line". FEBS Letters. 336 (1): 153–158. doi:doi:10.1016/0014-5793(93)81630-I.
{{cite journal}}: Check|doi=value (help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Carey, Francis A. (2006) [1987]. Organic Chemistry (6th ed. ed.). New York: McGraw Hill. p. 1149. ISBN 0-07-282837-4.
Amino acids are carboxylic acids that contain an amine function.
{{cite book}}:|edition=has extra text (help) - ^ Lahdesmaki, P (1987). "Biosynthesis of taurine peptides in brain cytoplasmic fraction in vitro". Int J Neuroscience. 37 (1–2): 79–84.
{{cite journal}}: Cite has empty unknown parameter:|1=(help) - ^ Militante, J. D. (2002). "Treatment of hypertension with oral taurine: experimental and clinical studies". Amino Acids. 23 (4): 381–393. doi:10.1007/s00726-002-0212-0. Retrieved 2006-08-22.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Currently taurine is being tested as an anti-manic treatment for bipolar depression. Tsuboyama-Kasaoka, Nobuyo (2006). "Taurine (2-Aminoethanesulfonic Acid) Deficiency Creates a Vicious Circle Promoting Obesity". Endocrinology. 147 (7): 3276–3284. doi:10.1210/en.2005-1007. Retrieved 2006-08-22.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Li F, Abatan OI, Kim H, Burnett D, Larkin D, Obrosova IG, Stevens MJ (2006 Jun). "Taurine reverses neurological and neurovascular deficits in Zucker diabetic fatty rats". Neurobiology of Disease. 22 (3): 669-676.
{{cite journal}}: Check date values in:|year=(help)CS1 maint: multiple names: authors list (link) - ^ Pop-Busui R, Sullivan KA, Van Huysen C, Bayer L, Cao X, Towns R, Stevens MJ (2001 Apr). "Depletion of taurine in experimental diabetic neuropathy: implications for nerve metabolic, vascular, and functional deficits". Exp Neurol. 168 (2): 259-272.
{{cite journal}}: Check date values in:|year=(help)CS1 maint: multiple names: authors list (link) - ^ Laidlaw S, Shultz T, Cecchino J, Kopple J (1988) "Plasma and urine taurine levels in vegans." American Journal of Clinical Nutrition, vol. 47, pp. 660-663.
- ^ "Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes". American Journal of Clinical Nutrition. Vol. 71 (No. 1): 54–58.
{{cite journal}}:|issue=has extra text (help);|volume=has extra text (help); Cite uses deprecated parameter|authors=(help); Text "date January 2000" ignored (help) - ^ "Taurine And Its Importance In Cat Foods". Iams Cat Nutrition Library. 2004. Retrieved 2006-08-22.
- ^ "Nutrient Requirements of Cats". Nutrient Requirements of Cats, Revised Edition, 1986. 1986. Retrieved 2006-09-10.