![]() The excretion of taurine in mammals takes place mainly via the kidney and the rate of excretion is closely related to dietary intake of the nutrient. While the distribution of taurine can differ markedly depending upon tissue/cell types, high levels of the compound are present in bile, intestine, heart, skeletal muscle, brain, nerve, liver, kidney, retina and leukocyts. This transporter is proposed to help maintain the intracellular concentrations of taurine. The active taurine transport system is stereospecific and is inhibited by β-amino acids (eg., β-alanine), guanidino ethane sulfonate (GES) and γ-amino butyric acid. In addition, at relatively high concentrations, taurine is also transported by diffusion. Both ingested and endogenous taurine is transported into the interiors of cells across plasma membrane by a high-affinity active transport system designated taurine transporter (TAUT). Taurine is readily absorbed from the gastrointestinal tract. Although humans can synthesize taurine, the majority of taurine stores derive from food sources of animal origin, especially eggs, meat and seafood. However, the biosynthetic capacity and turnover rate of taurine can vary significantly in different animal species (e.g., cats lack the ability for endogenous taurine biosynthesis while all others studied do not). Humans and animals can synthesize taurine from methionine and cysteine (or their precursors), primarily in the liver it is then delivered to target tissues by the circulation (1). Taurine was first isolated from the bile of ox (Latin Bos taurus) in 1827 by the Gerrnan scientists, Friedrick Triedemann and Leopold Gmelin. In humans, taurine is considered semi-essential since it can be synthesized endogenously. Further, taurine is not incorporated into protein structures. It is mostly found in free form in the cytosol and plasma, and the concentrations in these compartments in humans are 50-200 μM and 5-30 mM, respectively. Taurine (2-aminoethanesulfonic acid) is a naturally-occurring amino acid-like compound present in substantial amounts in many mammalian tissues. Elucidation of the mechanisms through which taurine affects the vasculature could facilitate the development of therapeutic and/or diet-based strategies to reduce the burdens of vascular diseases. ![]() ![]() In addition, the molecular mechanism (s) involved in the vascular effects of taurine is largely unknown and requires further investigations. However, despite these favorable findings, there is a need to further establish certain aspects of the reported results and also consider addressing unresolved related issues. Oral taurine in hypertensive human patients alleviates the symptoms of hypertension and also reverses arterial stiffness and brachial artery reactivity in type 1 diabetic patients. In endothelial cells, taurine inhibits apoptosis, inflammation, oxidative stress and cell death while increasing NO generation. In rat aortic vascular smooth muscle cells (VSMCs), taurine acts as an antiproliferative and antioxidant agent. Oral administration of taurine also ameliorates impairment of vascular reactivity, intimal thickening, arteriosclerosis, endothelial apoptosis, oxidative stress and inflammation, associated primarily with diabetes and, to a lesser extent with obesity, hypertension and nicotine-induced vascular adverse events. Consistent with this, taurine produces endothelium-dependent and independent relaxant effects in isolated vascular tissue preparations. These effects of taurine have been shown to be both centrally and peripherally mediated. Oral supplementation of taurine induces antihypertensive effects in various animal models of hypertension. This brief review summarizes the role of taurine in the vasculature and modulation of blood pressure, based on experimental and human studies. It exerts a diverse array of biological effects, including cardiovascular regulation, antioxidation, modulation of ion transport, membrane stabilization, osmoregulation, modulation of neurotransmission, bile acid conjugation, hypolipidemia, antiplatelet activity and modulation of fetal development. Taurine is a sulfur-containing amino acid-like endogenous compound found in substantial amounts in mammalian tissues.
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