Taurine attenuates nitric oxide- and reactive oxygen intermediate-dependent hepatocyte injury
H. P. Redmond, J. H. Wang and D. Bouchier-Hayes
Royal College of Surgeons in Ireland, Department of Surgery, Beaumont Hospital, Dublin, Ireland. surgres@iol.ie
OBJECTIVE: To evaluate the potential role of the semi-amino acid taurine in
the prevention of hepatocyte (HC) apoptosis and necrosis mediated by nitric
oxide (NO) and reactive oxygen intermediates. DESIGN: Isolated rat HCs were
cultured with lipopolysaccharide (LPS), antioxidants, taurine, and sodium
nitroprusside to examine the effect of these agents on HC injury. RESULTS:
Lipopolysaccharide, in the presence of antioxidants, led to HC apoptosis,
while LPS alone failed to induce HC apoptosis. Taurine significantly
attenuated LPS plus antioxidant-mediated HC apoptosis, and this correlated
with taurine-mediated NO inhibition. Taurine also significantly reduced
LPS-mediated hepatocellular enzyme release and HC necrosis, and this
correlated with HC free radical and peroxynitrite inhibition. However,
taurine did not prevent sodium nitroprusside-mediated HC apoptosis and
necrosis. CONCLUSIONS: Taurine attenuates HC apoptosis and necrosis through
inhibition of both NO and reactive oxygen intermediate. While taurine acts
directly as an antioxidant, its effects on NO may occur at the messenger
RNA level. Our findings indicate a potential prophylactic and therapeutic
role for this amino acid during systemic inflammatory response syndrome.
