TAURINE

'Taurine', or '2-aminoethanesulfonic acid', is an organic acid that is a major constituent of bile, and can be found in lower amounts in the tissues of many animals including humans. ^[1][2] Taurine is also found in plants, fungi, and some bacterial species, but at lower levels. Taurine is a derivative of the sulfur-containing (sulfhydryl) amino acid, cysteine.
Taurine is named after the Latin ''taurus'', which means bull, as it was first isolated from Ox bile in 1827 by Austrian scientists Friedrich Tiedemann and Leopold Gmelin. It is often called an ''amino acid'', even in scientific literature,^[3][4][5] but as it lacks a carboxyl group it is not strictly an amino acid.^[6] 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 incorporating it onto a tRNA.^[7] Also contrary to popular belief Taurine is not synthesized bull urine.

Contents

Physiological roles

Taurine and cats

Safety data

Energy drinks

References

External links

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,^[8] long-term potentiation in the striatum/hippocampus, membrane stabilization, feedback inhibition of neutrophil/macrophage respiratory bursts, adipose tissue regulation, and calcium homeostasis.
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.^[9]
Recent studies show that taurine supplements taken by mice on a high-fat diet prevented them from becoming overweight. Studies have yet to be done on the effect of taurine on obesity in humans. Currently taurine is being tested as an anti-manic treatment for bipolar depression.^[10] Recent studies have also shown that taurine can influence (and possibly reverse) defects in nerve blood flow, motor nerve conduction velocity, and nerve sensory thresholds in experimental diabetic neuropathic rats.^[11][12] 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%.^[13]
In recent years, taurine has become a common ingredient in energy drinks. Taurine is often used in combination with bodybuilding supplements such as creatine and anabolic steroids, partly due to recent findings in mice that taurine alleviates muscle fatigue in strenuous workouts and raises exercise capacity.^[14] Taurine is also used in some contact lens solutions.
Taurine has also been shown in diabetic rats to decrease weight and decrease blood sugar.^[15]

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).^[16][17]
In addition, taurine deficiency can cause feline dilated cardiomyopathy, and supplementation can reverse left ventricular systolic dysfunction. However, the vegetarian lioness Little Tyke survived for years in captivity without imbibing the normal required dose of Taurine.^[18] (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 0.1% 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 one gram of taurine corresponds to a concentration of about 4.083 ppm.

Energy drinks

Taurine is an ingredient in many energy drinks and energy products. It is present in the alcoholic drinks Sparks, Spykes, VK blue and Mobius Infused Lager. It is also contained in the energy drinks Monster (which contains 2000 mg of taurine, 1000 for each of the two servings), Von Dutch, RedBull, NOS (2750 mg), Boo Koo Energy (3000 mg), and XL. The Rockstar energy drink, distributed by the Coca-Cola Corp., can contain up to 2000 mg of taurine, depending on the flavor. It is in Foosh Energy Mints and Buzz Bites Chocolate Energy Chews. SoBe Power Fruit Punch contains 50mg of taurine, while SoBe Adrenaline Rush contains 960mg. It's also one of the main ingredients in the Indonesian energy powder Extra Joss. Power C Vitamin Water, from Glacéau's line of vitaminwater, contains 25 mg of taurine. Most recently, Glacéau has developed an energy drink, vitaminenergy, which contains 2000 mg of taurine per 16 oz can. Wired Energy Drinks X5000 contains 4400 mg of taurine in a 23.5 ounce can. Red Bull contains 1000 mg per 8.3 oz can. Both Hogan Energy Drink and WWE RAW Attitude Energy Drink Powered by Socko have 2000 mg of Taurine per can (1000 mg per serving). Amp energy drink contains only 10 mg per serving.
Despite its presence in many energy drinks, taurine has not been shown to be energy-giving, however the results of the studies into taurine usage have shown that taurine might help to reduce muscle fatigue.^[14]

References

1. Is taurine a functional nutrient?, Bouckenooghe T, Remacle C, Reusens B, , , Curr Opin Clin Nutr, 2006
2. The sulfur-containing amino acids: an overview., Brosnan J, buffalo bill Brosnan M, , , J Nutr, 2006
3. Host defense--a role for the amino acid taurine?, , PP, Stapleton, Journal of Parenteral and Enteral Nutrition, 1998
4. Chlorination of Taurine by Human Neutrophils, , Stephen J., Weiss, Journal of Clinical Investigation, 1982
5. Volume-regulatory taurine release from a human heart cancer cell line, , Kiaran, Kirk, FEBS Letters, 1993
6. Organic Chemistry, , Francis A., Carey, McGraw Hill, 2006, ISBN 0-07-282837-4
7. Biosynthesis of taurine peptides in brain cytoplasmic fraction in vitro., , P, Lahdesmaki, Int J Neuroscience, 1987
8. Olive MF. Interactions between taurine and ethanol in the central nervous system. Amino Acids 2002;23(4):345-57
9. Treatment of hypertension with oral taurine: experimental and clinical studies, , J. D., Militante, Amino Acids, 2002
10. Taurine (2-Aminoethanesulfonic Acid) Deficiency Creates a Vicious Circle Promoting Obesity, , Nobuyo, Tsuboyama-Kasaoka, Endocrinology, 2006
11. Taurine reverses neurological and neurovascular deficits in Zucker diabetic fatty rats., Li F, Abatan OI, Kim H, Burnett D, Larkin D, Obrosova IG, Stevens MJ, , , Neurobiology of Disease, 2006 Jun
12. Depletion of taurine in experimental diabetic neuropathy: implications for nerve metabolic, vascular, and functional deficits., Pop-Busui R, Sullivan KA, Van Huysen C, Bayer L, Cao X, Towns R, Stevens MJ, , , Exp Neurol., 2001 Apr
13. 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.
14. Taurine transporter knockout depletes muscle taurine levels and results in severe skeletal muscle impairment but leaves cardiac function uncompromised, U. Warskulat, U. Flogel, C. Jacoby, H.-G. Hartwig, M. Thewissen, M. W. Merx, A. Molojavyi, B. Heller-Stilb, J. Schrader and D. Haussinger, , , FASEB J., 2004
15. Taurine improves insulin sensitivity in the Otsuka Long-Evans Tokushima Fatty rat, a model of spontaneous type 2 diabetes, , , , American Journal of Clinical Nutrition,
16. Taurine And Its Importance In Cat Foods
17. Nutrient Requirements of Cats
18. The Vegetarian Lioness
19. Taurine transporter knockout depletes muscle taurine levels and results in severe skeletal muscle impairment but leaves cardiac function uncompromised, U. Warskulat, U. Flogel, C. Jacoby, H.-G. Hartwig, M. Thewissen, M. W. Merx, A. Molojavyi, B. Heller-Stilb, J. Schrader and D. Haussinger, , , FASEB J., 2004

External links

★ BBC report on possible uses of taurine and alcohol damage - 2005