Mesenteric lymph reperfusion after superior mesenteric artery occlusion shock exacerbates endotoxin translocation in brain.

PURPOSE: To determine the role of mesenteric lymph reperfusion (MLR) on endotoxin translocation in brain to discuss the mechanism of brain injury subjected to superior mesenteric artery occlusion (SMAO) shock. METHODS: Twenty-four rats were randomly assigned to MLR, SMAO, MLR+SMAO and sham groups. MLR was performed by clamping the mesenteric lymph duct (MLD) for 1 h and then allowing reperfusion for 2 h in the MLR group; SMAO involved clamping the superior mesenteric artery (SMA) for 1 h, followed by reperfusion for 2 h in the SMAO group; occlusion of both the SMA and MLD for 1 h was followed by reperfusion for 2 h in the MLR+SMAO group rats. RESULTS: SMAO shock induced severe increased levels of the endotoxin, lipopolysaccharide receptor, lipopolysaccharide-binding protein, intercellular adhesion molecule-1 and tumor necrosis factor-α. Concurrently, MLR after SMAO shock further aggravates these deleterious effects. CONCLUSION: Mesenteric lymph reperfusion exacerbated the endotoxin translocation in brain; thereby increased inflammatory response occurred, suggesting that the intestinal lymph pathway plays an important role in the brain injury after superior mesenteric artery occlusion shock.

Mesenteric lymph reperfusion after superior mesenteric artery occlusion shock exacerbates endotoxin translocation in brain

PURPOSE: To determine the role of mesenteric lymph reperfusion (MLR) on endotoxin translocation in brain to discuss the mechanism of brain injury subjected to superior mesenteric artery occlusion (SMAO) shock. METHODS: Twenty-four rats were randomly assigned to MLR, SMAO, MLR+SMAO and sham groups. MLR was performed by clamping the mesenteric lymph duct (MLD) for 1 h and then allowing reperfusion for 2 h in the MLR group; SMAO involved clamping the superior mesenteric artery (SMA) for 1 h, followed by reperfusion for 2 h in the SMAO group; occlusion of both the SMA and MLD for 1 h was followed by reperfusion for 2 h in the MLR+SMAO group rats. RESULTS: SMAO shock induced severe increased levels of the endotoxin, lipopolysaccharide receptor, lipopolysaccharide-binding protein, intercellular adhesion molecule-1 and tumor necrosis factor-α. Concurrently, MLR after SMAO shock further aggravates these deleterious effects. CONCLUSION: Mesenteric lymph reperfusion exacerbated the endotoxin translocation in brain; thereby increased inflammatory response occurred, suggesting that the intestinal lymph pathway plays an important role in the brain injury after superior mesenteric artery occlusion shock. .

[Role of endotoxin translocation on mesenteric lymph reperfusion aggravating multiple organ injury in SMAO shock rats].

OBJECTIVE: To investigate the role of mesenteric lymph reperfusion (MLR) aggravates multiple organs injury in superior mesenteric artery occlusion (SMAO) shock and its mechanism. METHODS: Twenty four Wistar rats were randomly divided into 4 groups (n = 6): Sham group (only anesthetized and operated), MLR group rats performed 1 h occlusion of mesenteric lymph duct (MLD), then followed by 2 h of reperfusion, SMAO group (rats performed 1 h occlusion of superior mesenteric artery (SMA) and then followed by 2 h of reperfusion), SMAO + MLR group (rats performed 1 h occlusion of SMA and MLD and then followed by 2 h of reperfusion). The blood sample was taken out from abdominal aortic for plasma and the liver, kidney, myocardium, lung tissues in fixed position were prepared for making homogenate after reperfusion of 2 h respectively. And the levels of endotoxin (ET) in plasma and homogenates were determined with kinetic turbidimetric technique of tachypleus amebocyte lysate, the contents of lipopolysaccharide-binding protein (LBP), lipopolysaccharide receptor (CD14) and tumor necrosis factor-alpha (TNF-alpha) in homogenates were determined with enzyme-linked immunosorbent assay method. RESULTS: The indices have no statistics difference between sham group and MLR group. The ET levels of the plasma and hepatic, renal, myocardial, pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than that of sham and MLR groups, and these indices in SMAO + MLR were increased significantly than those in SMAO group. The CD14, LBP and TNF-alpha contents of the hepatic, renal, myocardial and pulmonary homogenates in SMAO and SMAO + MLR groups were significant higher than those in sham and MLR groups, and these indices in SMAO+ MLR were higher than SMAO group significantly. CONCLUSION: The mechanism of MLR aggravates multiple organs injury in SMAO shock may be associated with enterogenous ET through intestinal lymphatic pathway to translocate, activate the LBP/CD14 as endotoxin sensitizing system and promote inflammatory response.

[Effect of mesenteric lymph duct ligation on erythrocyte rheology in acute hemorrhagic rats].

OBJECTIVE: To observe the effects of mesenteric lymph duct (MLD) ligation on erythrocyte rheology in acute hemorrhagic rats. METHODS: Twenty male Wistar rats were randomly divided into hemorrhage group and ligation group (n = 10). Blood (one fourth of body whole blood volume) was withdrawn through right common carotid arteries after rats were anesthetized. In ligation group, the MLD was ligated after hemorrhage, and only threading under the MLD in hemorrhage group. The survival situation at 24 h was recorded. After 24 h, survival rats were anesthetized again, blood sample was withdrawn through left common carotid artery rapidly. And the erythrocyte sedimentation rate (ESR), electrophoresis of erythrocytes, hematocrit (Hct) were determined in blood samples of before and after hemorrhage, the erythrocytes aggregation and deformability indices were calculated. RESULTS: It showed that the ligation group survival (9 rats alive) was slightly better than that in hemorrhage group (6 rats alive). The results of erythrocyte rheology indices showed that the ESR, K value of equation, K value of emendation and electrophoresis time in hemorrhage group and ligation group were higher or longer than those before hemorrhage, the erythrocyte deformability was reduced significantly, respectively. And the erythrocytes aggregation index in hemorrhage group was increased, the electrophoresis length and migration of erythrocyte in hemorrhage group were lower than those before hemorrhage, respectively. But compared with hemorrhage group, the ESR, K value of equation, K value of emendation, erythrocytes aggregation index and electrophoresis time in ligation group were lower, the electrophoresis lenght, migration and deformability of erythrocyte were increased significantly. CONCLUSION: The results indicate that the higher erythrocyte aggregation ability, lower electrophoresis function and deformability are caused by acute hemorrhage in rats, and the MLD ligation can improve the abnormal erythrocyte rheology.

[Effect of mesenteric lymph duct ligation on coagulability of blood after acute loss of blood in rats].

OBJECTIVE: To observe the effects of mesenteric lymph duct ligation on platelet function, thrombus formation in vitro and coagulation function in rats with acute loss of blood, and investigate the role of intestinal lymphatic pathway on coagulability change during acute loss of blood. METHODS: Twenty male Wistar rats were randomly divided into loss of blood group (n=10) and ligation group (n=10). The acute loss of blood model was reproduced by withdrawing blood (one fourth of body whole blood volume) with an automatic withdrawal-infusion machine through right common carotid artery. In ligation group, the mesenteric lymph duct was ligated after loss of blood, and in loss of blood group only a thread was passed under the mesenteric lymph duct. The rats' survival rate at 24 hours was recorded. After 24 hours, surviving rats were anesthetized again, and 6 ml of blood was with drew from left common carotid artery rapidly. The platelet adhesive rate, platelet aggregation rate, thrombus formation in vitro, coagulation function were determined before and after experiment, and the cerebral blood flow was measured. RESULTS: There were 6 rats alive in loss of blood group (60%), and 9 rats alive in ligation group (90%). The platelet adhesive rate, platelet aggregation rate, fibrinogen (Fib) content were increased in both groups, and cerebral blood flow was lower compared with before experiment significantly. The activated partial thromboplastin time (APTT) in loss of blood group, and thrombin time (TT) in both groups were prolonged. And the length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus and thrombus formation rate in loss of blood group were significantly increased compared with before experiment (P<0.05 or P<0.01). But in ligation group, the platelet adhesive rate [(15.02+/-1.24)%], platelet aggregation rate (at 1 minute, 3 minutes and max aggregation rate), length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus, thrombus formation rate [(46.2+/-6.9)%], APTT [(21.04+/-5.53)s] and Fib content [(433.67+/-13.97) g/L] were lower, cerebral blood flow [(485.1+/-41.4) ml x kg(-1) x min(-1)] was higher compared with loss of blood group, respectively [(18.54+/-1.18)%, (69.8+/-6.9)%, (26.35+/-6.26)s, (510.96+/-35.59) g/L, (417.8+/-42.2) ml x kg(-1) x min(-1), P<0.05 or P<0.01]. CONCLUSION: The results indicate that acute loss of blood leads to coagulation and increased thrombosis, and mesenteric lymph duct ligation can improve hypercoagulability of blood.