Modulation of endothelium-derived nitric oxide production and activity by taurine and taurine-conjugated bile acids

Publication date: Available online 24 October 2019Source: Nitric OxideAuthor(s): Daniele M. Guizoni, Jean F. Vettorazzi, Everardo M. Carneiro, Ana Paula DavelAbstractTaurine is a semiessential amino acid found at high concentrations in mammalian plasma and cells, where it regulates cellular functions such as ion flux, controls cell volume and serves as a substrate for conjugated bile acids (BAs). Exogenous administration of both taurine and taurine-conjugated BAs have also been implicated in the modulation of cardiovascular functions. This brief review summarizes the role of taurine and taurine-conjugated BAs in vascular relaxation through the modulation of endothelium-derived nitric oxide (NO). The effects of taurine on vascular health are controversial. However, in the presence of cardiometabolic risk factors, it has been proposed that taurine can increase vascular NO levels by increasing eNOS expression, eNOS phosphorylation on Ser1177, NO bioavailability, the level of antioxidative defense, and the l-arginine/NOS inhibitor asymmetric dimethylarginine (ADMA) ratio. The taurine-conjugated BA-mediated activation of Farnesoid X receptor (FXR), G protein-coupled BA receptor (TGR5) and/or muscarinic 3 receptor (M3) was also reported to increase vascular NO production. FXR activation increases eNOS expression and may reduce ADMA formation, while TGR5 increases mobilization of Ca2+ and phosphorylation of eNOS and AKT in endothelial cells. Furthermore, taurine and taurine-conjugat...
Source: Nitric Oxide - Category: Chemistry Source Type: research