PURPOSE:To investigate and changes of the retina and the chorid induced by lipopolysaccharide (LPS)in Lewis rats and to compare the results obtained on tissue wholemounts and sections. METHODS:Immunohistochemistry was carried out both on wholemounts of the retina and the chorid-sclera complex and on ocular sections from normal Lewis rats and those after LPS injection. RESULTS:It was shown on the tissue wholemounts that monocytes were attached to retinal blood vessels and emigrated into the choroid as early as 4hrs after LPS injection. Severe involvement of the retina and macrophages into whole area of these tissues.Furthermore increasing number of major histocompatibility complex classⅡ(MHC classⅡ)positive cells was observed in the choroid.The results on tissue sections revealed that the retina and the choroid were both involved as videnced by infiltration of these cells at some time points after LPS injection. CONCLUSION:Wholemount technique provides undoubtful evidences to show that the retina and choroid are primarily and severely involuted after LPS injection.The endotoxin induced uveitis is,for the first time,presumed to be model for human generalized uveitis. （Chin J Ocul Fundus Dis,1996,12:33-36）
To study the role of endotoxin in acute hemorrhagic necrotizing pancreatitis (AHNP), the change of endotoxin were studied in rats AHNP models by injection of 5% sodium taurocholate 1 ml/kg into pancreatic duct, and the effects of recombinant interleukin-2 (IL-2) in the treatment of AHNP were observed in this experiment. The results indicated that endotoxin involved the aggravation of AHNP and was associated with the increase of serum phospholipas-2 (PLA2), and these mediators were positively correlated with severe degrees of pancreatic damage. The results also suggeste that IL-2 might inhibit the overexpression of endotoxin and PLA2 and mitigate the pancreatic injury and decrease the 72h-mortality rate of AHNP from 66.7% to 26.7% (Ｐ＜0.01). Endotoxin might play a major role in the pathogenesis of AHNP and IL-2 might have a potential role in the treatment of AHNP.
Objective The effects of endotoxin, cytokines, nitric oxide were reviewed in the development of hyperdynamic circulatory syndrome in portal hypertension. Methods Liceratures of overseas main studies in hyperdynamic circulatory syndrome of portal hypertension in recent 10 years were reviewed. Results The hyperdynamic circulatory syndrome was found in 30%-50% of patients with cirrhosis and in all animal models of portal hypertension. The research results of the effects of endotoxin, cytokines, nitric oxide in the development of hyperdynamic circulatory syndrome were different. Conclusion Hyperdynamic circulatory syndrome contribute to the maintenance and aggregation of portal hypertension. Endotoxin, cytokines, nitric oxide may play a role in the development of hyperdynamic circulatory syndrome. Nitric oxide is a more important factor. The effect of other factors is probably mediated by nitric oxide.
Objective To observe the expression of matrix metalloproteinase-9 (MMP-9), its tissue inhibitor of matrix metalloproteinase (TIMP-1), inducible nitric oxide synthase (iNOS) and contents of nitric oxide (NO) in the ocular tissues of Sprague-Dawley (SD) rats with endotoxin induced uveitis（EIU）. Methods Ninety SD rats were randomly divided into experimental (81 rats) and control group (9 rats). The model of EIU was induced in rats in experimental group by injecting with lipoplysaccharide (LPS) 200 μl into the hind feet pads, while the rats in the control group were not injected. Nine rats were executed 0, 6, 12, 18, 24, 48, 72, 96 hours and 7 days, respectively, after injecting with LPS; the NO content and concentration of protein in the aqueous humor in blood plasma, aqueous humor, and uveal tissues were detected. The expressions of MMP-9, TIMP-1 and iNOS in the ocular tissues were detected by immunohistochemistry, and the average absorbance (A) value was evaluated by computer medical image analysis system. Results iNOS, MMP-9 and TIMP-1 expressed in the epithelial cells of iris and ciliary body and exudated inflammatory cells of rats. The concentration of protein in the aqueous humor, the contents of NO in blood plasma, aqueous humor, and uveal tissues, and A value of MMP-9 had obvious relativity with the inflammatory extent, while no positive correlation was found between the inflammatory extent and the A value of iNOS and TIMP-1. Expression of iNOS was found 6 hours after injection, reached the peak after 12 hours, and then dropped gradually. The expression of TIMP-1 could be seen 24 hours after injection, and reached its peak after 72 hours. Conclusion The content of NO and expressions of iNOS, MMP-9 and TIMP-1 changes from the beginning and during the development of EIU, which suggests that NO, iNOS, MMP-9 and TIMP-1 are involved in the pathologic process of EIU. (Chin J Ocul Fundus Dis, 2005, 21: 371-374)
Objective To investigate the effect of recombinant human growth hormone (rhGH) on intestinal bacteria and endotoxin translocation in experimental obstructive jaundice. MethodsObstructive jaundice rat models were made and divided into three groups: sham operation (SO) group, obstructive jaundice (OJ) group and obstructive with rhGH (OG) group. The number in each group was 20. The mice in rhGH group underwent subcutaneous injection each day of Saizen, with the dose of 0.75 u/kg, while SO group and OJ group received nitric sodium injection. All these maitained for 2 weeks, then the animals were killed and the endotoxin were determined by limulus test, and bacterial cultures of ascites, blood, mesenchymal lymph node, kidney, spleen and liver were made, and the height of villi and the thickness of intestinal walls were examined.ResultsThe value of endotoxin in OJ group was (0.77±0.03) u/ml, higher than that in OG group and SO group, while it was (0.40±0.02) u/ml and (0.33±0.03) u/ml (Plt;0.01). The bacteria translocation rate in OJ group was 58.8%, much higher than that in OG group, which was 10.0% (Plt;0.01). There was no difference between OG group and SO group (Pgt;0.05). Villi height in OJ group was (183.39±11.09) μm, and thickness was (255.62±16.58) μm. While in OG group was (237.52±13.65) μm, and (320.81±14.34) μm (Plt;0.01) respectively.Conclusion rhGH has significant effect on protecting the injuried mucosa barrier in obstructive jaundice, and can decrease endotoxemia and bacteria translocation.
【Abstract】Objective To investigate the preventive role of selective decontamination of the digestive tract (SDD) in gut-originated endotoxemia in acute necrotizing pancreatitis (ANP). Methods A lethal model of ANP was reproduced in Wistar rats by retrograde infusion of artificial bile into the main pancreatic duct. Normal control group (n=6), sham operation group (n=6), ANP group (n=14) and ANP+SDD (polymycin E, tobramycin and nystatin mixture) group (n=8) were randomly devided. Visceral pathologic changes, serum levels of TNFα and IL-1β, intestinal bacterial flora, plasma D(-)lactate and endotoxin contents, as well as the mortality were examined at 72h after operation in each group. Results Necrosis and inflammation of pancreas, with a remarkable elevation of serum TNFα and IL-1β and intestinal flora disturbance (with E.Coli content risen significantly) were seen in ANP rats. Simultaneously, ANP rats displayed elevated plasma concentration of D(-)lactate and endotoxin. In SDD group, enterobacteraceae and yeast were markedly depressed, while anaerobes were well preserved, with the value of B/E 〔Bifidobacterium/E.Coli, log10(CFU/CFU）〕 elevated in the ileac mucous membrane (1.73±1.23 vs -0.37±0.72 in ANP group,P＜0.01) and in the caecum content (∞ vs 0.88±0.77). In addition, depressed levels of D(-)lactate 〔（3.95±1.83） mg/L vs （8.05±3.05） mg/L in ANP group,P＜0.01〕, endotoxin 〔（0.227±0.084） EU/ml vs （0.423±0.155） EU/ml in ANP group, P＜0.01〕 and TNFα 〔（15.41±10.32） ng/L vs （46.79±24.31） ng/L in ANP group P＜0.01〕 in systemic or portal vein were observed in the SDD group. Moreover, SDD group displayed a declined 72h mortality(14.3% vs 58.8% in ANP group, P=0.005). Conclusion ANP is associated with gut barrier disorder and gut flora imbalance, which may exacerbate the process of gut-originated endotoxin translocation. By protecting gut flora and gut barrier against disorder, SDD attenuates ANPrelated endotoxemia and improves the outcome. SDD is advisable for the prophylaxis of gut-originated endotoxemia complicated from ANP.
ObjectiveTo explore the effect of endotoxin on insulin secretion from islet βcell of rat pancreas.MethodsAfter the model of endotoxemia was established in rats with intraperitoneal injection of LPS (2 mg/kg),the changes of insulin level in the serum and pancreas were dynamically determined, the expression of inducible nitric oxide synthase (iNOS) by situ hybridization and DNA damage in islet cells were also observed, the effect of sodium nitroprusside (exogenous NO) on synthesis and secretion of insulin from isolated islet βcell of normal rat pancreas under high glucose stimulation was also evaluated.ResultsThe level of glucose and insulin in plasma were significantly increased at 12th and 6th h, respectively and kept on 3 d after injection of LPS,but the insulin level in pancreas was not remarkably altered.The expression of iNOS and DNA damaged significantly enhanced at 6 d after endotoxemia. The high glucosestimulated insulin synthesis and secretion were bly inhibited by exogenous NO.ConclusionThese findings suggest that LPS be stimulate the expression of iNOS and NO product,which inhibites synthesis and secretion of insulin in islet βcells,but it stimulates insulin secretion by another mechanism,and results in dysfunction and destruction of the rat pancreas.
Objective To study the effect and intrinsic mechanism of acute suppurative peritonitis associated ascitic fluid (ASPAAF) on experimental liver injury of rats. Methods Thirty-two male or female Sprague-Dawley (SD) rats were randomly divided into two groups: ASPAAF group (n=16) and control group (n=16), in which 8 ml ASPAAF or normal saline (NS) were injected into the peritoneal cavity, respectively. The rats were killed at each time intervals after peritoneal cavity injection (6 h and 12 h) respectively in two groups and specimens were made to detect the levels of serum TNF-α, endotoxin and liver function (AST, ALT and STB). The level of TNF-α in liver tissues was measured. The pathological change of liver was observed by microscope. Results The levels of TNF-α, endotoxin, ALT, AST and STB in serum and the levels of TNF-α in liver tissues at different time points were markedly higher in ASPAAF group compared with those in control group (P＜0.05), and these indexes increased with increasing time in ASPAAF group (P＜0.05). In ASPAAF group, hepatic tissue appeared hydrops, even spotty necrosis and the changes at 6 h and 12 h were not obvious different. No abnormal pathological change of hepatic tissue was found in control group. Conclusion ASPAAF can induce the injury of the liver in rats, which may involved in TNF-α and endotoxin.
To observe the change in plasma endotoxin and cytokine during the early period of intra-abdominal infection (IAI) complicated by multiple system organ dysfunction (MSOD) in animals. Twenty rabbits were randomly divided in to two groups. One group received the operation of cecal ligation plus puncture (CLP) inducing IAI complicated by MSOD, and another group received sham operation as a control. All animals were placed in metabolic cages and maintained with intravenous infusion for one week. Plasma levels of endotoxin and cytokine (TNF, IL-1, IL-6) were determined seperately at the beginning (0 hour) or 1, 2, 3, 4, 5, 6 and 24 hours after CLP. Blood bacteria cultures and pathological examination of several organs were made when the animal was dead or killed. Results: The levels of plasma endotoxin, TNF and IL-6 were found to be significantly increased at one or two hours after CLP, the incidence rate of bacteriemia was 80% and the pathological alterations in the abdomen and organs were remarkale, with an average survival time of 84.1±39.0 hours in CLP group. No change in plasma IL-1 level was found in the CLP group. Conclusion: The plasma levels of endotoxin and cytokine (TNF and IL-6) do increase in the early period of IAI complicated by MSOD, and the change in plasma IL-1 is not obvious.
Objective To compare the in vitro inhibition activity of three mimic peptides at lipopolysaccharide binding protein (LBP)／CD14 binding sites for LPS-induced inflammatory response.Methods Enzyme-linked immunoSorbent assay(ELISA)was applied for the detection of the affinity between the mimic peptides and CD14 as well as the competitive inhibition activity of LBP.Mature U937 cells induced by PMA were co-cultured with LPS and intervened by mimic peptide.The effect of the mimic peptide on the TNF-α expression of U937 was detected by RT-PCR.Alveolar macrophages(AMs)of rats were co-cultured with FITC-LPS，and mimic peptide intervention was conducted.The effect of the mimic peptide on combination of LPS and AMs was observed by fluorescence microscope . Results Affinity between No.1 mimic peptide(FHRWPTWPLPSP，10 μg／mL)and CD14 was significantly higher than those of No.2 and No.3(20.3±4.1 11.8±2.4 and 13.7±3.3，Plt;0.01 or Plt;0.05).The competitive inhibitory activity of No.1 mimic peptide(10 μg／mL)for LBP was higher than those of No.2 and No.3[(57.2土11.2)％ vs(39.4±9.7)％ and(37.9±8.3)％ ，Plt;0.01].All of the three mimic peptides(10 μg／mL)could significantly inhibit the LPS-induced expression of TNF-α by U937 at mRNA level(Plt;0.01 or Plt;0.05)，moreover，the inhibitory activity of No.1 peptide was the highest(0.239±0.053 vs 0.406±0.112 and 0.493±0.121，Plt;0.01).In addition，No.1 mimic peptide markedly inhibited LPS combination with rat lung AMs(2157±514 vs 2763±453，plt;0.01).Conclusion No.1 mimic peptide(FHRWPTWPLPSP)have a relatively higher affinity with CD14 and high competitive inhibition activity for LBP，therefore it have the potential ability of anti-inflammatory response induced by LPS.