正正常肠淋巴液对内毒素休克小鼠多器官损伤的作用*

 目的： 观察正常肠淋巴液对内毒素休克小鼠肺、心、肝等器官损伤以及MAPK信号通路主要信号分子p38 MAPK、ERK1/2和JNK磷酸化水平的影响。方法: 引流18只BALB/c雄性小鼠正常肠淋巴液，去除细胞成分后用于内毒素休克的干预。18只小鼠均分为假休克组、内毒素休克组与肠淋巴液干预组（n=6）；腹腔注射脂多糖（LPS，35 mg/kg），复制小鼠内毒素休克模型；在LPS注射60 min后，淋巴液干预组小鼠经股动脉注射正常淋巴液（全血量的1/15）；整个实验过程监测平均动脉血压（MAP）；在腹腔注射LPS后6 h或相应时点，心尖穿刺取血，检测反映心肌和肝细胞损伤的生化指标；同时，留取固定位置的肺、心肌和肝组织，部分观察组织形态，部分检测p38 MAPK、ERK1/2和JNK的磷酸化水平。结果: 内毒素休克组与肠淋巴液干预组小鼠在腹腔注射LPS后90 min多个时点的MAP显著低于假休克组，肠淋巴液干预组小鼠MAP在腹腔注射LPS后80 min、90 min、190 min、210 min、240 min、250 min、340 min、350 min和360 min显著高于内毒素休克组。假休克组小鼠肺、肝和心肌组织结构基本正常，内毒素休克组小鼠出现了一定的结构损伤，肠淋巴液干预组小鼠组织损伤较轻；内毒素休克组小鼠血浆AST、ALT和CK-MB活性高于假休克组，肠淋巴液干预组小鼠血浆CK-MB活性亦高于假休克组，AST和LDH-1活性低于内毒素休克组。注射LPS后6 h，小鼠肺组织p38 MAPK、ERK 1/2和JNK的磷酸化水平显著升高，心肌和肝组织的这些指标未见显著变化；输入正常肠淋巴液降低了内毒素休克小鼠肺组织p38 MAPK以及心肌组织p38 MAPK、ERK 1/2和JNK磷酸化水平。结论: 输入正常肠淋巴液可减轻内毒素休克小鼠的器官损伤，降低肺组织p38 MAPK磷酸化水平。

Effect of normal mesenteric lymph on multiple organ injury in mice with endotoxic shock

AIM: To observe the effects of normal mesenteric lymph (NML) on the lung, heart and liver injuries and the phosphorylation levels of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) in the mice with endotoxic shock (ES). METHODS: The NML was drained form health male BALB/c mice for the intervention of ES after the removal of cellular constituent. Lipopolysaccharide (LPS, 35 mg/kg) was intraperitoneally injected into the mice for the establishment of ES model. After 60 min of LPS injection, the administration of NML (1/15 of whole blood volume) was performed through the femoral artery in NML+ES group. Meanwhile, the mean arterial pressure (MAP) was monitored during the experiment. At 6 h after intraperitoneal injection of LPS or the corresponding time point, blood samples were harvested from the heart through apical centesis for determination of the biochemical indexes to reflect myocardial and hepatocyte injuries. Simultaneously, the lung, heart and liver tissue specimens from a fixed location were harvested for the observation of histomorphology and the measurement of phosphorylation levels of p38 MAPK, ERK1/2 and JNK. RESULTS: Compared with sham shock (SS) group, MAP in ES group and NML+ES group remarkably decreased at multiple time points after intraperitoneal injection of LPS. However, MAP in NML+ES group at 80 min, 90 min, 190 min, 210 min, 240 min, 250 min, 340 min, 350 min, and 360 min were significantly increased compared with ES group. There were normal structures in the lung, liver and myocardium of the mice in SS group, while the morphological damages of these tissues appeared in ES group. Meanwhile, the damages were attenuated in the mice of NML+ES group. The activities of AST, ALT and CK-MB in the plasma in ES group were remarkably higher than those in SS group. The CK-MB activity in NML+ES group was also increased compared with SS group, and the activities of AST and LDH-1 were lower than those in ES group. At 6 h after LPS injection, the phosphorylation levels of p38 MAPK, ERK1/2 and JNK in the lung tissues were remarkably increased. Meanwhile, no statistical difference of these indexes between the myocardial and hepatic tissues was observed. NML intervention decreased the phosphorylation levels of p38 MAPK in the lung tissues, and p38 MAPK, ERK1/2 and JNK in the myocardial tissues. CONCLUSION: The NML administration alleviates multi-organ injuries and reduces the phosphorylation level of p38 MAPK in the lung tissues in the mice subjected to ES.