The Role Of Endothelial Bioreactor Device In Porcine Sepsis With Multiple Organ Dysfunction Syndrome

PARTⅠStudy of animal model of Multiple Organ Dysfunction Syndrome induced by endotoxin in porcinesBackgroundSepsis is a common and fatal disease,and is regarded to be a vicious expansion of the inflammatory response.Multiple organ dysfunction syndrome(MODS) is the hot topics in the field of surgical trauma and critical care medicine.MODS is a kind of acute organ injury which has the close association with stress such as shock and infection,and with uncontrolled systemic inflammatory and disorders of cell oxygen metabolism.Therefore sepsis and MODS are inseparable,its morbidity and mortality is always high for a long-term.Especially in the intensive care unit,sepsis and MODS is the main cause for death,so the research of sepsis is still a challenge in medical domain.At present the puzzled pathogenesis of sepsis leads to the lack of effective treatment of sepsis especially with MODS.So how to establish a reasonable animal model of sepsis may help to understand the development of sepsis and MODS,and to provide a strong evidence for resolving sepsis.At present there are many ways to establish the animal models of sepsis with MODS,and the purpose of this paper is to provide a simple and useful MODS animal model which was mediated by endotoxin.MethodsTen white cross pigs were anesthetized and mechanically ventilated.All the animals received intravenous lipopolysaccharide(0.25mg·kg-1) slowly through right internal jugular vein.Hemodynamics,blood routine,blood biochemistry and cytokines were examined at basement and at 1,2,3,4,5 and 6 h after the injection respectively.ResultsAfter the infusion of LPS,MAP was significantly lower at 6h than it before the infusion(p＜0.01),but the PA was raised continuously.Compared with the basement,the serum creatinine(SCr) and alanine aminotransferase(ALT) rised at 6h,and the prothrombin time(PT) prolonged 3s.Changes of cytokines such as IL-1,IL-10 and ET-1 were first raised slightly,then began to fall.However,the changes of sTM was inversely.ConclusionInfusion of LPS can induce porcine sepsis and lead to MODS in short term. PARTⅡThe role of endothelial bioreactor device in porcine sepsis with Multiple Organ Dysfunction SyndromeBackgroundIn the first part of this paper we have successfully constructed the animal model of sepsis with MODS in porcine.In our laboratory endothelial bioreactor device(BAD) has been established and the endothelial cells in this bioreactor device have been identified.Because endothelial cells in this bioreactor device exsist in the reactor's external cavity,then the blood through the reactor does not directly contact the endothelial cells,which effectively leads to the prevention of acute rejection.Much substance can be exchanged between inside and outside of the reactor cavity,and this exchange can be used by the endothelial cells in the bioreactor device to regulate the entire blood circulation.The purpose of this study is to prove the effectiveness of endothelial bioreactor device in porcine sepsis with MODS.MethodsWe picked up 10 white cross pigs and divided them into 2 groups randomly: sham group and endothelial bioreactor device(EBD) group.All the animals were anesthetized and mechanically ventilated.After the infusion of endotoxin(LPS,0.25 mg·kg^-1) to establish the sepsis model extracorporeal circulation began to run. Hemodynamics,blood routine,blood biochemistry and inflammatory parameters were examined at basement and at 1,3,6 h after the injection respectively.Hemodynamic parameters included mean arterial pressure(MAP),and serum biochemical parameters included serum creatinine(SCr) and potassium(K).Inflammation parameters included interleukin-1(IL-1) and 10(IL-10),endothelin-1(ET-1),nitric oxide synthase(NOs),and protein C(PC).The survival time of experimental animals was recorded at the last.ResultsAt 30 min after injection of LPS to 2 h,the drop of MAP of two groups was obvious,but MAP of EBD group then began to slowly increase,and could be maintained for a long time,and MAP of the sham group continued to decline.The differences between the two groups was significant(p＜0.01).After the start of the experiment,kidney function of the two group began to change,but it changed less in EBD group than in sham group.Even at the end of experiment SCr of EBD group has not significantly increased,while it was significantly increased in sham group(p=0.001).Changes in serum potassium was similar to SCr.At 6 h,serum potassium was significantly higher than that of EBD group,p=0.002.After the LPS infusion the concentration of IL-1 and IL-10 rised and arrived at the peak in two hours,and then began to decrease,and there was no difference between the two groups.The endothelin-1(ET-1) of EBD group decreased slowly first and began to rise after three hours,but nitric oxide synthase(NOs) began to increase first and decrease after two hours,while the changes of ET-1 and NOs in sham group was on the contrary.The survival time of EBD group and sham group was 5.5±0.3 and 6.7±0.4 d(p＜0.05).ConclusionEndothelial bioreactor device can not only improve hemodynamics of porcine sepsis,but also maintain the function of key organs,which lead to the prolongation of survival time of experimental animals. PARTⅢRole of endothelial bioreactor device in regulation of inflammatory cytokines of acute lung injury induced by endotoxin in porcineBackgroundIn the occurrence and development of sepsis,the uncontrol of inflammatory cytokines leads to multiple organ dysfunction syndrome(MODS),which thereby increases mortality.Among the injury organs,the lung usually happens the first and the easiest.In the pathogenesis of lung injury,the involvement of inflammatory cytokines plays a vital role,particularly including IL-1,IL-10 and TNF.These cytokines can promote the further injury of the lung tissue and cause the infiltration of neutrophil and the damage of lung epithelial cells,resulting in decreased function of alveolar capillary barrier and the increase of permeability,which culminates in acute respiratory distress syndrome(ARDS).In the second part of this research we have been successfully confirmed the effectiveness of endothelial cell bioreactor(BAD) in the treatment of porcine sepsis,and this effectiveness maybe achieve through the adjustment of cytokines.While cytokines are important in acute lung injury(ALI) induced by endotoxin,the initial purpose of this paper is to investigate the role of endothelial bioreactor device in regulating the inflammatory cytokines of acute lung injury induced by endotoxin.MethodsWe picked up 10 white cross pigs and divided them into 2 groups randomly: sham group and endothelial bioreactor device(EBD) group.All the animals were anesthetized and mechanically ventilated.After the infusion of endotoxin(LPS,0.25 mg·kg^-1) to establish the sepsis model extracorporeal circulation began to run. Interleukin-1 and 10 were examined at basement and at 1,3,6 h after the injection respectively.At the same time lung tissue from animals was obtained for HE staining, and the pathology specialist calculated the Lung Injury Score.Western blot was used to detect the protein content of TNF-αand tissue factor(TF) in the lung tissue.ResultsAfter injection of LPS,the concentration of IL-1 and IL-10 rised and arrived at the peak in two hours,and then began to decrease,and there was no difference between the two groups,but the decline was less in EBD group than in sham group.Compared with the EBD group in the lung pathology,there were more respiratory epithelial proliferation(REP),alveolar hemorrhage(AH) and vascular thrombosis(VT) in sham group.The lung injury score in sham group was much higher than in EBD group(8.2±1.0 vs 6.1±0.9,p=0.0447).In the lung tissue,protein content of tissue TNF-αin the treatment group was lower than in sham group(p＜0.05),but there was no significant difference between two group in the protein content of TF.ConclusionEndothelial bioreactor device can not only improve the hemodynamics of porcine sepsis,but also can reduce the expression of TNF-αin the lung tissue,which extenuates inflammation response in the lung tissue inflammation and postpones lung injury.