外源性硫化氢对大鼠移植肺细胞凋亡的影响

Effect of exogenous hydrogen sulfide on apoptosis of pneumonocytes in rats after lung transplantation

目的探讨外源性硫化氢(H2S)对大鼠移植肺细胞凋亡的影响。方法以硫氢化钠(NaHS)作为外源性H2S供体,将30只Sprague-Dawley雄性大鼠随机分入3组。假手术组(6只),开胸游离左肺门,未行肺移植;肺移植组(12只,供体、受体各6只),供体肺4℃冷缺血3h后开放再灌注2h;NaHS干预组(12只,供体、受体各6只),于再灌注开放前1h腹腔注射浓度为7mmol/L的NaHS溶液14μmol/kg,其余同肺移植组。再灌注2h后取移植肺组织,应用脱氧核苷酸末端转移酶介导的缺口末端标记技术(TUNEL法)检测细胞凋亡情况并计算凋亡指数(AI),应用实时反转录-聚合酶链反应(RT-PCR)检测各组肺组织中凋亡相关基因B细胞淋巴瘤/白血病(Bcl)-2和Bcl-2相关X蛋白(Bax)的mRNA表达,并计算Bax/Bcl-2比值。结果肺移植组和NaHS干预组的AI分别为(18.63±3.41)%、(6.57±1.89)%,均显著高于假手术组的(2.16±0.78)%(P值均<0.05);NaHS干预组的AI显著低于肺移植组(P<0.05)。肺移植组和NaHS干预组的Bax/Bcl-2比值分别为1.83±0.48、1.47±0.39,均显著高于假手术组的1.01±0.17(P值均<0.05);NaHS干预组的Bax/Bcl-2比值显著低于肺移植组(P<0.05)。结论外源性H2S可减少大鼠移植肺缺血再灌注后的细胞凋亡,这可能是H2S在大鼠肺移植后肺缺血再灌注损伤中发挥保护性作用的机制之一。

Objective To explore the effect of exogenous hydrogen sulfide （H2S） on apoptosis of pneumonocytes in rats after lung transplantation （LTx）. Methods Thirty male Sprague-Dawley rats were randomly divided into three groups sham operation group （n = 6, only receiving thoracotomy and ventilation）, LTx group and H2S group （including 6 donors and 6 recipients, respectively）. We performed single left LTx in all rats after 3 h of cold ischemia in LTx group. In H2S group, H2S donor Naris （14 μmol/kg） was intraperitoneally administered 1 h before reperfusion. An equivalent volume of normal saline was given in the sham operation group. The apoptosis of pneumonocytes was estimated at 2 h after reperfusion by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique （TUNEL）, and the apoptotic index was calculated. In addition, apoptosis regulatory genes B cell lymphoma/leukemial-2 Bcl-2, anti-apoptosis and （Bcl-2 associated X protein Bax, pro-apoptosis） were further estimated by reverse transcriptase polymerase chain reaction, and the ratio of Bax to Bcl-2 was calculated. Results The apoptotic index was （ 18.63 ± 3.41 ） % in the LTx group, （6.57±1.89）% in the H2 S group, and （2.16±0.78） % in the sham operation group. The apoptotic index in the lung-transplanted rats was significantly higher than that in the sham operation group （P〈0.05）, but the apoptotic index in the H2 S group was significantly lower than that in the LTx group （P〈0.05）. The ratio of Bax to Bcl-2 was 1.83±0.48 in the LTx group, 1.47±0.39 in the H2S group, and 1.01±0.17 in the sham operation group. The Bax/Bcl-2 ratio in the lung-transplanted rats was significantly higher than that in the sham operation group （P〈 0.05）, while the ratio in the H2 S group was significantly lower than that in the LTx group （P〈0.05）. Conclusion Exogenous H2S can decrease the apoptosis of pneumonocytes after LTx, which may be one of the mechanisms for cytoprotection against lung ischemical reperfusion injury. （Shanghai Med J, 2013, 36 ; 833-836）