ABSTRACT

Taurine, a semi-essential and sulphur-containing β-amino acid, is not incorporated into proteins. It has been shown in many in vitro and in vivo studies to have cytoprotective effects, and these actions are often attrib-uted to an antioxidant mechanism. The purpose of this study was to investigate the effect of taurine on 3-nitroty-rosine production and xanthine oxidase activity in hepatocytes during endotoxemia.

In this study, 40 adult male Dunkin Hartley guinea pig were randomly divided into four groups: con-trol, taurine, endotoxemia and taurine plus endotoxemia (n=10). Animals were administered taurine (300 mg/kg, a single dose), lipopolysaccharide (4 mg/kg), or taurine plus lipopolysaccharide intraperitoneally. After six hours of incubation, when the highest blood levels of taurine and endotoxin were attained, the animals were sacrificed and liver samples were collected. The amount of 3-nitrotyrosine was measured by HPLC and xanthine oxidase enzyme activity was measured spectrophotometrically.

Lipopolysaccharide administration significantly increased protein 3-nitrotyrosine levels and xanthine oxi-dase activity in hepatic tissue compared with the control group (p<0.05). In the taurine plus endotoxemia group, taurine and lipopolysaccharide administration significantly reduced protein 3-nitrotyrosine levels and xanthine oxidase activity compared with the endotoxemia group (p<0.05).

It has been concluded that taurine prevented the formation of protein nitration in hepatocytes. Tau-rine may act as a biological antioxidant not only by decreasing xanthine oxidase activity but also by scavenging peroxynitrite. (Gazi Med J 2011; 22: 14-7)