Abstract Purpose: To investigate the effect of mesenteric lymph drainage on the spleen injury and the expressions of inflammatory cytokines in splenic tissue in mice following hemorrhagic shock. Methods: Male C57 mice were randomly divided into the sham shock, shock and shock+drainage groups. The mice in both shock and shock+drainage groups suffered femoral artery bleeding, maintained mean arterial pressure (MAP) of 40±2 mmHg for 90 min, and were resuscitated. And mesenteric lymph drainage was performed in the shock+drainage group at the time of resuscitation. After three hours of resuscitation, the splenic tissues were harvested for the histological observation and protein and mRNA expression analysis of cytokines. Results: The spleen in the shock group revealed a significantly structural damage and increased mRNA expressions of MyD88 and TRAF6 and protein expressions of TIPE2, MyD88, TRIF and TRAF3 compared to the sham group. By contrast, the splenic pathological injury in the shock+drainage group was alleviated significantly, and the mRNA and protein expressions of TIPE2, MyD88, TRIF, TRAF3 and TRAF6 were significantly lower than those in the shock group. Conclusion: These results indicate that post-hemorrhagic shock mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and the expressions of inflammatory cytokines.

PURPOSE: This study was conducted to investigate the effect of normal mesenteric lymph (NML) from mice on the spleen injury induced by lipopolysaccharide (LPS) challenge.METHODS: Mice in the LPS and LPS+NML groups received an intraperitoneal injection of LPS (35 mg/kg) and kept for 6 h.. The mice in the LPS+NML group received NML treatment at 1 h after LPS injection. Afterward, the splenic morphology, the levels of lipopolysaccharide-binding protein (LBP), cluster of differentiation 14 (CD14), phosphorylation mitogen-activated protein kinases (MAPKs), and inflammatory mediators in splenic tissue were investigated.RESULTS:LPS injection induced spleen injury, increased the levels of LBP, CD14, tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interferon γ (IFN-γ), and decreased the IL-4 content in the spleen. By contrast, NML treatment reversed these changes. Meanwhile, the LPS challenge decreased the phosphorylation levels of p38 MAPK, extracellular regulated protein kinases 1/2, and c-Jun N-terminal kinase (JNK). Moreover, the phosphorylation levels of p38 MAPK and JNK were further decreased by the NML administration.CONCLUSION:rRdThe normal mesenteric lymph treatment alleviated lipopolysaccharide induced spleen injury by attenuating LPS sensitization and production of TNF-α, IL-6, and IFN-γ.

PURPOSE:To evaluate whether post-hemorrhagic shock mesenteric lymph (PSML) is involved in cardiac dysfunction induced by hemorrhagic shock.METHODS: The hemorrhagic shock model (40±2 mmHg, 3h) was established in rats of the shock and shock+drainage groups; and PSML drainage was performed from hypotension 1-3h in the shock+drainage rats. Then, the isolated hearts were obtained from the rats for the examination of cardiac function with Langendorff system. Subsequently, the isolated hearts were obtained from normal rats and perfused with PSML or Krebs-Henseleit solution, and the changes of cardiac function were observed.RESULTS:The left ventricular systolic pressure (LVSP) and the maximal rates of LV developed pressure (LVDP) rise and fall (±dP/dtmax) in the shock and shock+drainage groups were lower than that of the sham group; otherwise, these indices in the shock+drainage group were higher compared to the shock group. In addition, after isolated hearts obtained from normal rats perfusing with PSML, these cardiac function indices were gradual decline along with the extension of time, such as heart rate, LVSP, ±dP/dtmax, etc.CONCLUSION:Post-hemorrhagic shock mesenteric lymph is an important contributor to cardiac dysfunction following hemorrhagic shock.

PURPOSE:To evaluate the changes of contractility and reactivity in isolated lymphatics from hemorrhagic shock rats with resuscitation.METHODS: Six rats in the shock group suffered hypotension for 90 min by hemorrhage, and resuscitation with shed blood and equal ringer's solution. Then, the contractility of lymphatics, obtained from thoracic ducts in rats of the shock and sham groups, were evaluated with an isolated lymphatic perfusion system using the indices of contractile frequency (CF), tonic index (TI), contractile amplitude (CA) and fractional pump flow (FPF). The lymphatic reactivity to substance P (SP) was evaluated with the different volume of CF, CA, TI and FPF between pre- and post-treatment of SP at different concentrations.RESULTS:The CF, FPF, and TI of lymphatics obtained from the shocked rats were significantly decreased than that of the sham group. After SP stimulation, the ∆CF (1×10-8, 3×10-8, 1×10-7, 3×10-7mol/L), ∆FPF (1×10-8, 3×10-8, 1×10-7 mol/L), and ∆TI (1×10-8 mol/L) of lymphatics in the shock group were also obviously lower compared with the sham group. In addition, there were no statistical differences in CA and ∆CA between two groups.CONCLUSION: Lymphatic contractility and reactivity to substance P appears reduction following hemorrhagic shock with resuscitation.

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.

PURPOSE: To evaluate the role of exogenous normal lymph (ENL) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats.METHODS:ALI was induced by the jugular vein injection of LPS (iv, 15 mg/kg) in rats of the LPS and LPS+ENL groups within 15 min, then, ENL without cell components (5 ml/kg) was infused at the speed of 0.5 ml per minute in the LPS+ENL group, the same amount of saline was administered in the LPS group. The rats in the sham group received the same surgical procedure and saline. The histomorphology and the levels of P-selectin, intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) in pulmonary tissue were assessed.RESULTS: LPS induced pulmonary injury as well as increased the wet/dry weight ratio (W/D) and the levels of P-selectin, ICAM-1, and MPO in pulmonary tissues. These deleterious effects of LPS were significantly ameliorated by ENL treatment.CONCLUSION: Exogenous normal lymph could markedly alleviate the acute lung injury induced by lipopolysaccharide, and its effects might be related to lessening the adhesion molecules.

PURPOSE: To investigate the role of protein kinase G (PKG) in blocking post-shock mesenteric lymph (PSML) return ameliorating the calcium sensitivity in hemorrhagic shock rats. METHODS: Male Wistar rats were randomly divided into sham, shock, shock+ligation (shock plus mesenteric lymph duct ligation (MLDL)), shock+drainage (shock plus PSML drainage) groups. After shock (hypotension 40mmHg) for three hours or corresponding times, the superior mesenteric artery (SMA) was taken out for detecting the PKG and phospho PKG (p-PKG) contents, and the vascular rings of SMA were prepared for assaying the calcium sensitivity using an isolated organ perfusion system. RESULTS: The PKG and p-PKG contents of SMA in shock group were significantly increased than that of sham group, and MLDL or PSML drainage reducing the levels of PKG and p-PKG. Meanwhile, the vascular calcium sensitivity in shock group was significantly lower than that of sham group, MLDL or PSML drainage enhanced the calcium sensitivity. After incubating with PKG regulators in shock+ligation and shock+drainage groups, the PKG agonist 8Br-cGMP reduced the contractility of vascular rings to gradient calcium ions and Emax and the PKG inhibitor agonist KT5823 elevated the calcium sensitivity significantly. CONCLUSION: Protein kinase G plays an important role in post-shock mesenteric lymph blockage improving vascular calcium sensitivity.

Disturbances of the microcirculation and abnormal hemorheological properties are important factors that play an important role in disseminated intravascular coagulation (DIC) and result in organ dysfunction or failure. In the present study, we established an animal model of DIC using intravenous Dextran 500 in rats, and used exogenous normal lymph corresponding to 1/15 of whole blood volume for injection through the left jugular vein. We found that normal lymph could improve the blood pressure and survival time of rats with DIC. The results regarding the mesenteric microcirculation showed that the abnormality of the diameter of mesenteric microvessels and micro-blood flow speed in the DIC+lymph group was significantly less than in the DIC+saline group. Whole blood viscosity, relative viscosity, plasma viscosity, hematocrit (Hct), erythrocyte sedimentation rate (ESR), and electrophoresis time of erythrocytes were significantly increased in the DIC+saline group compared to the control group. The electrophoretic length and migration of erythrocytes from the DIC+saline and DIC+lymph groups were significantly slower than the control group. Blood relative viscosity, Hct, ESR, and electrophoretic time of erythrocytes were significantly increased in the DIC+lymph group compared to the control group. Whole blood viscosity, relative viscosity and reduced viscosity were significantly lower in the DIC+lymph group than in the DIC+saline group, and erythrocyte deformability index was also significantly higher than in the DIC+saline and control groups. These results suggest that exogenous normal lymph could markedly improve the acute microcirculation disturbance and the abnormal hemorheological properties in rats with DIC induced by Dextran 500.