AIMTo study the effect of taurine (Tau) on rabbit cardiomyocyte apoptosis during ischemia/reperfusion (I/R) injury.

METHODSRabbit heart I/R injury was induced by occluding the left anterior descending coronary artery for 45 min and reperfusion for 180 min. taurine (200 mg/kg) was intravenously injected 5 min before heart ischemia. Cardiomyocyte apoptosis was measured by using terminal deoxynucleotidyl transferase--mediated dUTP nick end labeling method (TUNEL), flow cytometry (FCM) and DNA agarose gel electrophoresis.

RESULTSDNA ladder pattern of DNA in myocardium was revealed by agarose gel electrophoresis in I/R group while was not found in Tau + I/R group. Apoptotic cardiomyocytes were sparse within ischemic myocardium at risk in Tau + I/ R group as compared with that in I/R group (TUNEL stain). Apoptosis rate in ischemic myocardium from I/R and Tau + I/R groups detected by flow cytometry was 17.66% +/- 1.54% and 4.86% +/- 1.23%, respectively. Fas and Bax protein expressions in ischemic myocardium of I/R group were higher than that in nonischemic myocardium group (P < 0.01), Bcl-2/Bax ratio in I/R group was lower than that in nonischemic myocardium (P < 0.01); while in Tau + I/R group, Fas and Bax protein expressions were lower than that in I/R group (P < 0.01), the Bcl-2/Bax ratio was higher than that in I/R group (P < 0.01).

CONCLUSIONTaurine reduced apoptosis of myocytes in I/R rabbit heart; its mechanism may involve Fas, Bax and Bcl-2 proteins expression.