胸导管淋巴液引流对大鼠SAP并肺损伤的保护作用及机制

Beneficial effect of thoracic duct lymph drainage on lung injury secondary to severe acute pancreatitis in rats and its mechanism

目的:探讨胸导管淋巴液引流对重症急性胰腺炎(SAP)并急性肺损伤大鼠的保护作用及机制。方法:72只SD大鼠随机均分为假手术组,SAP模型组(SAP组)和SAP模型+胸导管引流组(引流组),SAP模型采用逆行胰胆管注射5%牛磺胆酸钠的方法,引流组行胸导管淋巴液持续引流。分别于造模后4,8,14 h每组各取8只大鼠,分别检测淋巴液、血浆内毒素(ET)水平,肺组织病理学变化及NF-κBp65蛋白的表达。结果:除假手术组外,SAP组和引流组8 h后均出现肺损伤,但引流组明显轻于SAP组。4 h时各组淋巴液ET水平未见明显差异(P>0.05),但SAP组与引流组淋巴液ET水平均随时间延长不断升高,两组8,14 h的淋巴液ET水平均明显高于假手术组(均P<0.05),但相同时间点上,引流组ET水平明显低于SAP组(均P<0.05),假手术组各时间点淋巴液ET水平无明显变化(P>0.05);各组血浆ET水平与淋巴液ET水平呈现相同变化趋势,且两者ET水平呈明显正相关(4 h时r=0.7857,P=0.0208;8 h时r=0.7233,P=0.0426;14 h时r=0.9048,P=0.002)。4 h时各组肺组织NF-κBp65表达量无统计学差异(P>0.05),8,14 h时SAP组及引流组NF-κBp65表达量均明显高于假手术组(均P<0.05),但引流组NF-κBp65表达量增加程度明显低于SAP组(均P<0.05)。结论:SAP并肺损伤时胸导管淋巴液内毒素水平及和肺组织NF-κB表达均明显升高,胸导管淋巴液引流对减轻肺损伤有积极作用。

Objective： To investigate the effect of thoracic duct lymph drainage on lung injury induced by severe acute pancreatitis（SAP） and its mechanism. Methods： Seventy-two SD rats were randomized into sham operation group,SAP model group（SAP group） and SAP model plus thoracic duct lymph drainage group（drainage group）.SAP model was induced by retrograde injection of 5% sodium taurocholate into biliopancreatic duct,and rats in drainage group underwent continuous thoracic duct lymph drainage.Eight rats in each group were sacrificed at 4,8 and 14 h after surgery,respectively.The endotoxin（ET） levels in the lymphatic fluid and plasma were measured,the pathological changes of rats＇ lung tissues were assessed and NF-κBp65 protein expressions in lung tissues were also detected. Results： Except for sham operation group,rats in both SAP group and drainage group exhibited remarkable lung injury 8 h later,which in drainage group was less evident than that in SAP group.The lymphatic ET levels in each group showed no significant difference at the 4-h time point,but were increased in both SAP group and drainage group with time prolongation,which were significantly higher than those in sham operation group at 8-and 14-h time points（all P〈0.05）.The lymphatic ET levels in sham operation group showed no difference at the three observation time points（P〈0.05）.The change patterns of plasma ET levels in each group were similar to those in the lymphatic fluid,and the plasma ET levels were significantly positively correlated with the lymphatic ET levels（4 h： r=0.7857,P=0.0208;8 h： r=0.7233,P=0.0426;14 h： r=0.9048,P=0.0002）.The NF-κBp65 protein expression levels showed no significant difference among groups at the 4-h time point,but were significantly increased in both SAP group and drainage group compared with sham operation group at 8-and 14-h time points（all P〈0.05）.The elevation degrees of NF-κBp65 expression in drainage group were significantly lower than those in SAP group at both time points（both P〈0.05）. Conclusion： The lymphatic ET and NF-κB expression levels in lung tissues increase significantly in rats with lung injury secondary to SAP,and thoracic duct lymph drainage is a positive treatment modality for this condition.