Mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and inflammation

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.

Enhanced cyclooxygenase-2 activity leads to intestinal dysmotility following hemorrhagic shock

ABSTRACT PURPOSE: To test whether hemorrhagic shock (HS) increases the Cyclooxygenase-2 (COX-2) expression in the intestine and whether this enhanced COX-2 expression mediates the intestinal dysmotility after HS. METHODS: Male Wistar rats were randomly divided into HS sham group and HS group. At 180 min following HS establishment, the duodenum samples were harvested to assess the motility function, protein expression of COX-2 and the downstream products of COX-2, prostaglandins. RESULTS: Examination of motility function ex vivo showed that the contractile response to acetylcholine of smooth muscle strips of rats subjected to HS was significantly suppressed. A COX-2 inhibitor, NS-398, abolished this depressed contractile response after HS. Western blotting revealed an increased protein expression of COX-2 in intestinal tissues of HS rats. Immunohistochemical examination indicated that intestine tissues of HS rats were manifested by part of villous expansion and disruption, a large amount of COX-2 positive cells appearance in lamina propria and submucosa. Furthermore, the contents of prostaglandin E2 was significantly increased in intestinal tissues of HS rats. CONCLUSION: The enhanced COX-2/ prostaglandin E2 involves in the hemorrhagic shock induced intestinal dysmotility.

Normal mesenteric lymph ameliorates lipopolysaccharide challenge-induced spleen injury

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.

Reduction of contractility and reactivity in isolated lymphatics from hemorrhagic shock rats with resuscitation

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, 3×10-7 mol/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. .

Role of protein kinase G on the post-shock mesenteric lymph blockage ameliorating vascular calcium sensitivity

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.