Effect of intestinal lymphatic circulation blockage in two-hit rats

Post-shock mesenteric lymph drainage ameliorates cellular immune function in rats following hemorrhagic shock

Disturbance of immunity is an important factor to modulate inflammatory responses after severe shock. Post-shock mesenteric lymph (PSML) return plays an adverse role in multiple organ injuries induced by the hemorrhagic shock, and the inflammatory factors are involved in this process. However, whether the PSML can exacerbate immune dysfunctions that modulate inflammatory response to the hemorrhagic shock remains unknown. In the present study, the effects of PSML drainage on the distribution of T lymphocyte subgroup, the release of inflammatory factors, and apoptosis of thymocytes were investigated; the effect of PSML on the specific parameters of cellular immune function was also determined. Results showed that PSML drainage reduced the increased levels of CD3+, CD3+CD4+, CD4+CD25+ lymphocytes, IFN-γ, and the ratios of CD3 + CD4+/CD3 + CD4- in blood of the shocked rats at 3 h after resuscitation; PSML drainage also abolished the decreased IL-4 level and restored the higher ratio of IFN-γ/IL-4 to normal levels. Tissue injury, including enlarged intermembrance space and edema with congestion in the medulla, increased apoptotic cells and bax expression, decreased number of cells in the S phase, and bcl-2 expression were observed in the thymus after hemorrhagic shock. PSML drainage reversed these effects. In particular, PSML drainage increased the proliferation index and decreased p53 expression of thymocytes. These results suggest that hyperimmunity occurred at early stages of hemorrhagic shock with resuscitation and that PSML drainage could markedly improve cellular immune function that is responsible for the reduced inflammatory responses.

Changes in renal tissue proteome induced by mesenteric lymph drainage in rats after hemorrhagic shock with resuscitation

Kidney injury commonly occurs after hemorrhagic shock. Previous studies have shown that post-hemorrhagic shock mesenteric lymph (PHSML) return negatively affects the kidneys and may induce injury. This study investigates the effect of PHSML drainage on the proteome in renal tissue. A controlled hemorrhagic shock model was established in the shock and shock+drainage groups. After 1 h of hypotension, fluid resuscitation was implemented within 30 min. Meanwhile, PHSML was drained in the shock+drainage group. After 3 h of resuscitation, renal tissue was extracted for proteome analysis using two-dimensional fluorescence difference gel electrophoresis. Differential proteins with intensities that either increased or decreased by 1.5-fold or greater were selected for trypsin digestion and analyzed by matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and tandem TOF/TOF mass spectrometry. Enzyme-linked immunosorbent assay was used to validate the identified partial proteins. Compared with the sham group, hnRNPC and Starp decreased in the shock group, whereas Hadha, Slc25a13, Atp5b, hnRNPC, Starp, Rps3, and actin were downregulated in the shock+drainage group. Meanwhile, Atp5b and actin decreased in the shock+drainage group relative to the shock group. The identified proteins can be classified into different categories, such as cell proliferation (hnRNPC, Strap, and Rps3), energy metabolism (Hadha, Atp5b, and Slc25a13), cell motility, and cytoskeleton (actin). Moreover, enzyme-linked immunosorbent assay measurement validated the changed levels of Atp5b and Actg2. Our findings provide a starting point for investigating the functions of differentially expressed proteins in acute kidney injury induced by hemorrhagic shock. These findings hold great potential for the development of therapeutic interventions.

Hydrogen sulfide in posthemorrhagic shock mesenteric lymph drainage alleviates kidney injury in rats

Posthemorrhagic shock mesenteric lymph (PHSML) is a key factor in multiple organ injury following hemorrhagic shock. We investigated the role of hydrogen sulfide (H₂S) in PHSML drainage in alleviating acute kidney injury (AKI) by administering D,L-propargylglycine (PPG) and sodium hydrosulfide hydrate (NaHS) to 12 specific pathogen-free male Wistar rats with PHSML drainage. A hemorrhagic shock model was established in 4 experimental groups: shock, shock+drainage, shock+drainage+PPG (45 mg/kg, 0.5 h prehemorrhage), and shock+drainage+NaHS (28 µmol/kg, 0.5 h prehemorrhage). Fluid resuscitation was performed after 1 h of hypotension, and PHMSL was drained in the last three groups for 3 h after resuscitation. Renal function and histomorphology were assessed along with levels of H₂S, cystathionine-γ-lyase (CSE), Toll-like receptor 4 (TLR4), interleukin (IL)-10, IL-12, and tumor necrosis factor (TNF)-α in renal tissue. Hemorrhagic shock induced AKI with increased urea and creatinine levels in plasma and higher H₂S, CSE, TLR4, IL-10, IL-12, and TNF-α levels in renal tissue. PHSML drainage significantly reduced urea, creatinine, H₂S, CSE, and TNF-α but not TLR4, IL-10, or IL-12. PPG decreased creatinine, H₂S, IL-10, and TNF-α levels, but this effect was reversed by NaHS administration. In conclusion, PHSML drainage alleviated AKI following hemorrhagic shock by preventing increases in H₂S and H₂S-mediated inflammation.

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 duct ligation after hemorrhagic shock enhances the ATP level and ATPase activity in rat kidneys

BACKGROUND

Kidney injury commonly occurs following hemorrhagic shock. This study aims to observe the effects of mesenteric lymph duct ligation (MLDL) on the adenosine triphosphate (ATP) levels and the cell membrane adenosine triphosphatase (ATPase) activity in the kidneys of rats subjected to hemorrhagic shock.

METHODS

Wistar rats were assigned into sham, shock, and ligation groups. The hemorrhagic shock model was established in the shock and ligation groups, and MLDL was performed in the ligation group after resuscitation. Renal homogenates were prepared to determine the ATP and ATPase levels at 90 min after hemorrhage and at 0, 1, 3, 6, 12, and 24 h after resuscitation.

RESULTS

The ATP levels, and the Na(+)-K(+)-ATPase, Mg(2+)-ATPase, Ca(2+)-ATPase, and Ca(2+)-Mg(2+)-ATPase activities in the renal tissue of the shock group were lower than those in the sham group at the multiple time points. Furthermore, the corresponding values in the ligation group were significantly higher than those in the shock group at multiple time points.

CONCLUSION

MLDL improves energy metabolism and enhances the ATPase activity in the kidneys of hemorrhagic shock rats, along with other mechanisms that alleviate renal injury after hemorrhagic shock.

Mesenteric lymph drainage alleviates acute kidney injury induced by hemorrhagic shock without resuscitation

This study aimed to investigate the effect of mesenteric lymph drainage on the acute kidney injury induced by hemorrhagic shock without resuscitation. Eighteen male Wistar rats were randomly divided into sham, shock, and drainage groups. The hemorrhagic shock model (40 mmHg, 3 h) was established in shock and drainage groups; mesenteric lymph drainage was performed from 1 h to 3 h of hypotension in the drainage group. The results showed that renal tissue damage occurred; the levels of urea, creatinine, and trypsin in the plasma as well as intercellular adhesion molecule-1 (ICAM-1), receptor of advanced glycation end-products (RAGE), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), lactic acid (LA), and 2,3-DPG in the renal tissue were increased in the shock group after 3 h of hypotension. Mesenteric lymph drainage lessened the following: renal tissue damage; urea and trypsin concentrations in the plasma; ICAM-1, RAGE, TNF-α, MDA, and LA levels in the renal tissue. By contrast, mesenteric lymph drainage increased the 2,3-DPG level in the renal tissue. These findings indicated that mesenteric lymph drainage could relieve kidney injury caused by sustained hypotension, and its mechanisms involve the decrease in trypsin activity, suppression of inflammation, alleviation of free radical injury, and improvement of energy metabolism.

Postinjury multiple organ failure

Postinjury multiple organ failure (MOF) became prevalent as the improvements in critical care during the 1970s made it possible to keep trauma patients alive with single organ injury. Enormous efforts invested in laboratory and clinical research made it possible to better understand the epidemiology and pathophysiology of the syndrome. This has translated to improved strategies in prediction, prevention and treatment of MOF. With changes in population demographics and injury mechanisms and improvements in trauma care, changes in the epidemiology of MOF are also becoming evident. Significant improvements in trauma patient management decreased the severity and mortality of MOF, but the syndrome still remains the most significant contributor of late postinjury mortality and intensive care unit resource utilisation. This review defines the essential MOF-related terminology, summarises the changing epidemiology of MOF, describes our current understanding of the pathophysiology, discusses the available strategies for prevention/treatment based on the identified independent predictors and provides future directions for research.