PDTC对急性坏死性胰腺炎大鼠急性肺损伤的影响

目的:探讨四氢化吡咯烷二硫代氨基甲酸酯(PDTC)对急性坏死性胰腺炎(ANP)大鼠急性肺损伤的影响。方法:36只成年SD大鼠随机均分为:假手术组,ANP组,PDTC预处理组。ANP模型采用逆行胰胆管注射5%牛磺胆酸钠的方法,PDTC预处理组在造模前l h腹腔注射PDTC(30 mg/kg)。术后6 h处死动物,经支气管肺泡灌洗获取肺泡巨噬细胞(AMs),用流式细胞仪检测AMs凋亡情况,免疫组化和Western blot法测定AMs中NF-κB和CYLD活性水平;检测支气管肺泡灌洗液(BALF)中TNF-α和IL-1β含量;同时行肺组织病理学检查和肺组织髓过氧化物酶(MPO)水平检测。结果:假手术组肺组织未见病理改变,ANP组和PDTC预处理组肺组织均出现充血、水肿、炎性渗出等病理改变,但PDTC预处理组病变程度轻与ANP组;ANP组肺组织的MPO活性,以及BALF的TNF-α,IL-1β含量较假手术组明显升高(均P<0.05),而PDTC预处理组上述指标的升高被明显抑制,与ANP组比较,差异有统计学意义(均P<0.05);假手术组,ANP组,PDTC预处理组AMs凋亡率分别为(3.47±1.45)%,(1.16±0.31)%,(1.80±0.60)%,各组间差异有统计学意义(均P<0.05);免疫组化显示,AMs中的NF-κB在假手术组、ANP组、PDTC预处理组分别呈弱阳性、强阳性、中等阳性表达;假手术组,ANP组,PDTC预处理组AMs的NF-κB的相对表达量分别为0.08±0.03,0.18±0.06,0.13±0.04,各组间差异均有统计学意义(均P<0.05),3组CYLD的相对表达量分别为0.32±0.09,0.15±0.05,0.26±0.08,假手术组与ANP组间差异有统计学意义(P<0.05),但与PDTC预处理组间差异无统计学意义(P>0.05);ANP组,PDTC预处理组AMs中NF-κB与CYLD的表达活性均呈负相关(r=-0.708,r=-0.481,均P<0.05)。结论:PDTC可能通过抑制NF-κB的活化从而诱导ANP大鼠肺泡巨噬细胞凋亡,并增强NF-κB负性调控因子CYLD的表达,进而减轻肺损伤。

Effect of PDTC on acute lung injury secondary to acute necrotizing pancreatitis in rats

Objective: To investigate the effect of pyrrolidine dithiocarbamate(PDTC) on acute lung injury secondary to acute necrotizing pancreatitis(ANP) in rats. Methods: Thirty-six adult SD rats were equally randomized into the sham operation group,ANP group and ANP+PDTC pretreatment group.ANP model was induced by retrograde injection of 5% sodium taurocholate into biliopancreatic duct,and the animals of the PDTC pretreatment group were intraperitoneally injected with PDTC(30 mg/kg) l hour prior to ANP induction.All the animals were sacrificed 6 hours after model establishment,the alveolar macrophages(AMs) were harvested via bronchoalveolar lavage(BAL),and then the apoptosis of AMs was detected by flow cytometer and the activation levels of NF-κB and CYLD in AMs was determined by immunohistochemistry and Western blot method.The contents of TNF-α and IL-1β in the bronchoalveolar lavage fluid(BALF) were also detected.Meanwhile,the myeloperoxidase(MPO) levels of the lung tissues were measured,and pathological assessment of the lung tissues was performed. Results: No pathological change was noted in lung tissues of the sham operation group,while the lung tissues of both the ANP and PDTC pretreatment group showed marked pathological changes such as congestion,edema and accumulation of inflammatory exudates,but these changes of the PDTC pretreatment group were relatively mild compared with those of the ANP group.The MPO activity in the lung tissues,and the contents of TNF-α and IL-1β in the BALF were all significantly increased in the ANP group compared with the sham operation group(all P<0.05),while the elevations of the above parameters were markedly inhibited in the PDTC group and their differences with the ANP group had statistical significance(all P<0.05).The apoptosis rates of AMs of the sham operation group,ANP group and PDTC group were(3.47±1.45)%,(1.16±0.31)% and(1.80±0.60)% respectively,and the differences among the groups had statistical significance(all P<0.05).The immunohistochemical staining indicated that the NF-κB in the AMs of the sham operation group,ANP group and PDTC group presented weak positive,strong positive and moderate positive expression,respectively.The relative expression levels of NF-κB of the sham operation group,ANP group and PDTC pretreatment group were 0.08±0.03,0.18±0.06 and 0.13±0.04 respectively,and the differences among the groups had statistical significance(all P<0.05).The relative expression levels of CYLD of the three groups were 0.32±0.09,0.15±0.05 and 0.26±0.08 respectively,in which there was statistical significant difference between the sham operation group and ANP group(P<0.05) and no significant difference between the sham operation group and PDTC pretreatment group(P>0.05).There were negative correlations between the expression of NF-κB and CYLD in the AMs of the ANP group and PDTC pretreatment group(r=–0.708 and r=–0.481,both P<0.05). Conclusion: PDTC can induce the apoptosis of AMs by inhibiting NF-κB activation and enhancing the expression of NF-κB negative regulator CYLD,and thereby ameliorate the lung injury secondary to ANP.