牛磺酸对肢体缺血再灌注后大鼠肝损伤中Bcl-2、Bax蛋白表达的影响

Effects of taurine on Bcl-2 and Bax expressions in rats with liver injury after limb ischemia-reperfusion

目的观察大鼠肢体缺血再灌注(limb ischemia-reperfusion,LIR)后肝损伤中细胞凋亡及Bcl-2、Bax蛋白表达变化,探讨肝损伤的发生机制及牛磺酸的保护效应。方法健康雄性Wistar大鼠30只,随机分为对照组、缺血再灌注(IR)组、牛磺酸+缺血再灌注(TR)组,每组10只。测定各组肝组织MDA、MPO及钙含量的改变;采用免疫组织化学方法检测Bcl-2、Bax蛋白表达情况;采用TUNEL检测凋亡百分率。结果 与对照组比较,IR组大鼠肝组织MDA、MPO、钙含量均明显升高,Bax蛋白表达明显增强,Bcl-2蛋白表达略增强,Bcl-2/Bax比值下降,凋亡百分率明显升高。与IR组相比,TR组肝组织Bax蛋白表达明显下调,Bcl-2蛋白表达增强,Bcl-2/Bax比值升高,其他各损伤指标均有所下降。结论 牛磺酸可减轻大鼠LIR所致肝损伤及细胞凋亡的发生,其机制可能与减少氧自由基产生、维持钙稳态、提高Bcl-2/Bax比值水平有关。

Objective To investigate changes of Bcl-2 and Bax expressions and apoptosis in liver injured rats following limb ischemia-reperfusion（LIR）, and explore the preventive effect of taurine on liver injury. Methods 30 healthy male Wistar rats were randomly divided into 3 groups： the control group, the IR group and the taurine ＋ IR （TR） group （ n = 10 in each）. The levels of MDA, MPO and calcium in liver tissues were measured. Expressions of Bcl-2 and Bax in liver tissues were tested by the immunohistochemical method. Apoptosis was detected by the TUNEL method Resuits It was found that compared with the control group, test values of MDA, MPO and calcium and the percentage of apoptosis cells significantly increased in the IR group and TR group, while values of those in the TR group were lower than in the IR group. Immunohistochemistry revealed that the ratio of Bcl-2/Bax was lower in the IR group than in the control group, while the ratio of Bcl-2/Bax was significantly higher and the percentage of apoptosis cells was significantly lower in the TR group than in the IR group. Conclusion Taurine may have a protective effect on liver cells and can reduce occurrence of apoptosis after hind limb ischemia repeffusion injury in rats. The mechanism may be that it decreases generation of oxygen free radicals and overload of calcium, and increases expressions of Bcl-2 and Bax genes.