Expression Of TLR4mRNA In The Ischemia/Reperfusion Heart And Protective Effect Of N-acetylcysteine

Objective To investigate the expression of TLR4mRNA in the course of cardiac ischemia-reperfusion (I/R) and the protective effect of NAC.Method Forty-eight SD rats were divided randomly into no NAC-treated group(oh,2h,4h,6h; six rats every time course) and NAC-treated group(oh,2h,4h,6h; six rats every time course). Hearts were rapidly isolated and placed into 4℃K-H(Kreb's-Henseleit) buffer for 1h,then perfused at Langendorff apparatus for corresponding time course. Immunohistochemical method and western blot were used to detect the expression of NF-κB,Caspase-3 and RT-PCR was used to detect the mRNA level of TLR4 of myocardial tissue.Result In the no NAC-treated group, the mRNA level of TLR4 in heart perfused for 4h was significantly higher than that in heart perfused for 0h,2h and 6h and the expression of NF-κB and Caspase-3 both increased with time. In the NAC-treated group, there were no significantly variance of mRNA level of TLR4 of defferent time course. In the same time course, the expression of NF-κB and caspase-3 of no NAC-treated group were less than that of NAC-treated group.Conclusion TLR4mRNA participated in the pathological precess of cardiac ischemia-reperfusion (I/R) injury and NAC can reduce this injury by inhibit the mRNA level of TLR4.