What is taurine ?
Taurine is a sulfur-containing organic acid and one of the few naturally occurring sulfonic acids.
Taurine is found in large quantities in the mammalian body and plays an important role in the cardiovascular system, the development and function of muscles, the retina and the central nervous system. The body's production of taurine is usually limited; in diabetics is the consumption increased.
Classification as an amino acid
Taurine is a metabolic product of the amino acids cysteine and methionine, which both contain a thiol group. Taurine is often called an amino acid, but since taurine does not contain carboxyl group, it is no amino acid in the strict sense. It does include a sulfonic acid group and is, therefore, an aminosulphonic acid. Nevertheless, the scientific community classified as amino acid taurine, and for that reason taurine in scientific publications regularly appointed as amino acid. When it is classified among the amino acids, taurine is one of the most common free amino acids in various body tissues. An adult human being has about 1 gram per kilogram of body weight of taurine in the body.
Because the sulfone group no peptide bond may enter, taurine is not incorporated into proteins.
The structure of taurine is similar to that of gamma-aminobutyric acid (GABA) and choline, both of which are important for brains, and nerve tissue.
Taurine is excreted in the urine, or via the bile and bile salts.
History
Taurine is for the first time in 1827 by the chemists Friedrich Tiedemann and Leopold Gmelin isolated from gall (a bull or Bos taurus) by boiling with water. On the basis of similar physical and chemical properties of the compound they called initial gall-asparagine. In 1838 the name "taurine" was first used in the scientific literature. The name comes from the Latin word for bull, taurus. On this rather fortuitous resulting name has probably the creation of taurine to thank numerous legends about its origin and effect.
The importance of taurine in the diet of humans was discovered in 1975, when it became clear that preterm infants were unable to maintain adequate taurine levels.
Resources
Own synthesis
Taurine is considered a non-essential nutrient because adult humans can synthesize it in the body itself from the amino acid L-cysteine or L-methionine. This happens especially in the liver, but also can make the astrocytes in the brains (to a lesser extent) in taurine. The synthesis of taurine from cysteine or methionine can take place along three different routes, for all three is pyridoxal 5'-phosphate, the metabolically active form of vitamin B6 in question as a cofactor. Vitamin B6 deficiency inhibits the taurineaanmaak.
The enzyme cysteine sulfienzuurdecarboxylase (CSAD), turn both cysteine into sulfinic as cysteic in hypotaurine. The activity of this enzyme is representative of the extent to which the body is able to create taurine. Compared to other mammals, humans have a very low CSAD activity and thus a lower capacity for taurinesynthese. In cats this enzyme is completely lacking, they also lack a different capacity to produce taurine. Therefore taurine for them is essential. For that reason, a lot of research into the effects of taurine in cats run. Rodents have just a very high endogenous production of taurine.
Premature babies born lack the enzymes necessary to convert cystathionine to cysteine to, hence that taurine is essential for them. In babies and young children is the ability to make their own taurine still underdeveloped. For this reason, it is also added to infant formula. Babies who do not (yet) able to make enough taurine, get enough from breastfeeding or infant formula. Breast milk contains a concentration of taurine of between 25 and 50 milligrams per liter.
Because adults sometimes there are situations may arise in which a shortage of own synthesis (eg sometimes with physical exhaustion, illness or injury), taurine is often considered "conditionally essential".
Prevent
Taurine is basically in all body tissues, in almost all species. It is not incorporated into proteins, and is primarily intracellularly present, dissolved in the cytosol and bound to cell membranes.
Tissues with the highest taurineconcentraties are white blood cells (mainly neutrophils) and platelet counts, in brain tissue and nervous tissue, and in the retina. The largest amounts of taurine (in quantitative terms) are found in muscle tissue (especially the heart muscle).
Taurine is one of the most abundant amino acids in the brains. In the heart muscle consists more than 50% of the free amino acids stock from taurine, in the retina, it is slightly less than half of the free amino acids stock. These high taurineconcentraties are maintained by active transport of taurine into the intracellular space.
Sources in the diet
Taurine is mainly found in protein-rich animal foods such as meat, fish, shellfish, poultry and eggs. In particular, shellfish have a high content of taurine. Milk and milk products are less rich in taurine.
Taurine is not present in vegetable protein: beans and nuts do not contain taurine, but methionine and cysteine, which can be converted in the body into taurine.
Breast milk contains per liter, a concentration of between 25 and 50 milligrams of taurine.
Also, a relatively large amount of taurine incorporated into most types of energy drink. (Often 0.3% to 0.4%, so about 3 to 4 grams of taurine per liter)
The average daily intake via an omnivorous diet has been estimated to be about 58 mg (varies between 9 and 372 mg), and low or negligible at a strictly vegan diet. In another study, the taurine intake was estimated from food on average less than 200 mg / day, even in individuals who eat a lot of meat. According to another investigation, the intake of taurine ranged between 40 and 400 mg / day.
Deficiency
Taurinedepletie at taurinedeficiënte cats caused verschillene pathological conditions such as retinal degeneration, infertility, and cardiomyopathy. In humans taurine deficiency occurred in children receiving parenteral nutrition for a long time or in patients with blind loop syndrome.
The taurinestatus may be suboptimal in:
-An inadequate intake of nutrients necessary for the biosynthesis of taurine, such as vitamin B6, or an inadequate conversion of these nutrients in an active form (eg. In the conversion of vitamin B6 pyridoxal-5-phosphate).
-A vegetarian or vegan diet. Vegans get through diet virtually no taurine in, but normally make itself sufficient to prevent a deficiency. Nevertheless, have been found in vegans significantly lower taurine levels: Plasma concentrations and urinary concentrations were 78% to 29% of that of a control group on the standard diet.
-An increased taurinebehoefte, for instance due to illness.
Features
-Membrane stabilization: Taurine keeps the mineral balance of the cell in mode (potassium and magnesium within the cell, and sodium and calcium outside the cell), which is of great importance for the membrane potential and thereby the functionality of muscles, including the heart muscle. For this reason, taurine is also used in the treatment of epilepsy, as well as in people with uncontrollable facial spasms.
-Mechanism of contraction of the heart: Taurine is one of the most important nutrients for the heart. The membrane stabilizing activity mentioned above plays an important role in the contractile mechanism of the heart and thereby the functionality of the heart muscle. There is evidence that cardiac arrhythmias are a symptom of taurine deficiency.
-Diabetes: There is increasing evidence for the effectiveness of taurine in both diatebes type 1, type 2 diabetes and insulin resistance, particularly from animal studies. In addition, supplementation with taurine appears beneficial in diabetic complications including retinopathy, nephropathy, neuropathy, atherosclerosis and cardiomyopathy.
-Cardiovascular disease: There is much evidence from experimental animal studies and a few human studies that taurine protects against (worsening) cardiovascular disease. Taurine has a blood lipid-lowering and anti-atherogenic action and also goes against the formation of gallstones. There appears to be a clear link between higher taurineinname and reduced mortality from ischemic heart disease.
-Bile acid metabolism: Taurine plays an important role in bile acid metabolism. Taurine increases the activity of the rate-limiting enzyme cholesterol 7-alfahydroxylase in the liver, which is responsible for degradation of cholesterol into bile acids. This taurine promotes galzuurconjugatie, allowing more bile acids are excreted with the feces and decreases the risk of gallstones. This, however, relates to a relatively small proportion of the total body stock taurine.
-Eyepiece: Taurine plays an important role in the lens of the eye and in the retina (retinal) in humans and other mammals.
-Blood pressure: In the most commonly used animal models of high blood pressure has been shown that taurine lowers blood pressure. There are indications that a suboptimal taurinestatus enhances the pressor effect of salt. Also taurine in animal studies hypertension goes by alcohol or cyclosporin A against. In small trials in humans is a blood pressure lowering effect is also shown, namely in doses of six grams per day. There is strong evidence that taurine has an influence on blood pressure via the central nervous system. Taurine inhibits the release of the vasoconstrictor hormone ADH by the hypothalamus when there is stress. Another mechanism of action is that taurine has an influence on the local renin-angiotensin system, and in this way lowers blood pressure.
-Neurotransmitter: Along with glycine and gamma-aminobutyric acid (GABA) has taurine range of properties of an inhibitory neurotransmitter in the brains. Taurine can bind to glutamate receptors, and thereby to ensure that the cell is less vulnerable to excited. Taurine can pass the blood-brain barrier. Animal studies indicate an anxiolytic effect (anxiety reduction). Possible anxiolytic taurine acts via activation of the glycine receptor. Taurine meets most, if not all of the criteria which must meet a neurotransmitter. Or taurine actually can be regarded as a neurotransmitter is still a subject of debate.
-Brain metabolism: Taurine is synthesized in brain cells and plays a very important role in the development and growth of the brains. It stimulates the neuronal development, not only in the embryonic brains, but also in certain parts of the brain (the subventricular zone) in adults. In mice, and possibly also in humans, taurine stimulates neurogenesis. Taurine acts in various ways on brain tissue protective (neuroprotective) at a stroke.
-Antioxidant: Taurine is a strong antioxidant. It reduces oxidative stress because it binds hypochlorite.