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.
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 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)
ObjectiveTo investigate the regulatory roles and changes of M3 receptor subtype in lipopolysaccharide (LPS)-preincubated rabbit pulmonary arteries, and assess the mechanism of altered vascular reactivity in septic shock.
MethodsPulmonary arteries with intact endothelium were isolated from 26 male New ealand white rabbits weighing 2.0 to 2.5kg. he isolated pulmonary arteries were randomized into two grouops, including a normal group with normal saline and darifenacin adminstration, and an endotoxin group with LPS-preincubation and darifenacin adminstration.he response of arteries to phenylephrine (100μmol/L) and acetylcholine(ACH)(1μmol/L, 10μmol/L, 100μmol/L)were measured in normal and darifenacin-preincubated circumstances.
ResultsThe percentages of ralaxation to ACH (1μmol/L, 10μmol/L, 100μmol/L) were (0.095±0.034)%, (0.150±0.036)%, and (0.445±0.090)% in the normal group, and (0.044±0.016)%, (0.093±0.029)%, (0.311±0.028)% in the endotoxin (LPS 4μg/mL, 4h) group. After pretreatment with M3 receptor antagonist darifenacin on different concentrations, the EC50 values responding to ACH (1μmol/L, 10μmol/L, 100μmol/L) were 1.483, 2.757, 2.958 in the normal group, and 6.015, 6.242, 6.411 in the endotoxin group. After pretreatment with M3 receptor antagonist darifenacin on different concentrations, the inherent activity of a value to ACH (1μmol/L, 10μmol/L, 100μmol/L) were 0.0146, 0.0323, 0.0825 in the normal group, and 0.0124, 0.0245, 0.0556 in the endotoxin group.
ConclusionsLPS pre-incubation can reduce the relaxation response to ACH, and M3 receptor subtypes mediated this relaxation response. LPS also reduce the M3 receptor subtype intrinsic activity, which may be one of the mechanisms of decreased relaxation response to ACH in pulmonary arteris after LPS pretreatment, and also one of the mechanisms of pulmonary hypertension in septic shock.
In this article, the first time use of continuous veno-venous hemofiltration(CVVH) combined with toxic absorption for the treatment of a crush syndrome patient injured in earthquake is described. Correct therapeutic regimen, close observation and prescription condition are crucial for the success of management. The evidence for the application of this method is also discussed in detail.
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）
Objective To observe barrier function changes of gut mucosa in rats with acute respiratory distress syndrome(ARDS)．Methods Forty SD rats were randomized to an experiment group (n：30)and a control group(n=10)．Oleic acid was injected via vena femoralis to establish ARDS ratmode1．Subgroups in the experiment group were randomly divided by time 30 min，2 h，4 h interval after injection(n=10 in each subgroup)．Concentration of D-lactate and endotoxin and activity of diamineoxidase in blood plasma were measured．Histopathological changes of small intestine were observed under light microscope．Results Compared with the control group，the activation of diamine oxidase in the experiment group was higher after 30 min of injection(Plt;0.01)．Concentration of D-lactate，the activity ofdiamine oxidase and endotoxin level in the experiment group were all elevated after 2 hours of injection(all Plt;0.05)，and further elevated after 4 hours．In the rats’villous interstitial after 2 hours of the injection，there were edema，hyperemia，and infiltration of neutrophils，eosinophils and lymphocytes．After 4 hours ofthe injection，the villous epithelium showed desquamation，necrosis，denaturalization and erosion，associated with infihration of lymphocytes and neutrophils in the mucosa．Conclusion In oleic acid-induced ARDS．permeability of gut mueosa increases and gut barrier is dysfunctional．
【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.
The purpose of this study was to determine the contribution of endotoxin (ET) in ocurrence and progression of acute pancreatitis (AP). The results indicated that correlation of ET changes with multiple organ damage in AP. The degree of ET elevation correlated well with the severty of AP. The level of plasma ET of severe AP patients was much higher than that of mild AP patients (Ｐ＜0.05). The chance of multiple organ damage got greater while the plasma ET level got higher. Moreover, the severety change of severe AP correlated with the change of plasma ET level. In other words, the ET level was reduced while the disease was recovering, elevated while it was becoming worse and maintained high level in dead cases. We think that plasma ET level can be used as a reference for differenciating mild AP with severe AP and a predictor for the prognosis of AP.
TO investigate the relationship between endotoxemia and structural change in the pancreatic tissue and therapeutic effects of naltrexone (NTX) on experimental acute hemorrhagic necrotizing pancreatitis in rats. The model of acute hemorrhagic necrotizing pancreatitis (AHNP) of rats was induced by retrograde injection of 5% sodium taurocholate into the pancreatic duct. One hundred and ten Wistar rats were randomly divided into three groups: control group (n=20),AHNP group (n=45) and NTX treatment (n=45) group. The weight of pancreas and plasma levels of amylase and endotoxin were measured as well as changes of the pancreatic histology were examined by light and electric microscope in 6h, 12h, 24h after operation. Results as compared with control groups , amylase and endotoxin in AHNP group were significantly higher in the plasma and the damage to pancreatic tissue was increased in severity as observed with light and electric microscopes in 6h, 12h, 24h after operation. Comparison between NTX treatment groups with AHNP groups demonstrated that amylase and endotoxin were significantly decreased in the plasma, and the damage to pancreatic tissue was reduced in NTX treatment phase. Conclusion these results showed that endotoxemia was induced by AHNP, but NTX decreased the edotoxin level in the plasma and improved the damage of pancreatic tissue. The lethality was significantly lowered and average survival time was prolonged during NTX treatment of AHNP.
