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 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.
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 investigate the relationship of pulmonary surfactant protein D( SP-D) with chronic obstructive pulmonary disease ( COPD) by measuring SP-D level in serum and lung tissue of rats with COPD.Methods The rat COPD model was established by passive smoking as well as intratracheal instillation of lipopolysaccharide ( LPS) . Thirty male SD rats were randomly divided into a control group, a LPS group, and a COPD group( n =10 in each group) . The pathologic changes of lung tissue and airway were observed under light microscope by HE staining. Emphysema changes were evaluated by mean linear intercept ( MLI) of lung and mean alveolar number ( MAN) . The level of SP-D in serum was measured by enzymelinked immunosorbent assay ( ELISA) . The expression of SP-D in lung tissue was detected by Western-blot and immunohistochemistry.Results The MLI obviously increased, and MAN obviously decreased in the COPD group compared with the control group ( Plt;0.05) . There was no significant difference in the MLI and MAN between the LPS group and the control group ( Pgt;0.05) . The serum SP-D level was ( 49.59 ±2.81) ng/mL and ( 53.21±4.17) ng/mL in the LPS group and the COPD group, which was significantly higher than that in the control group [ ( 42.14±2.52) ng/mL] ( Plt;0.05) . The expression of SP-D in lung tissue was 0.56±0.01 and 0.63±0.01 in the LPS group and the COPD group, which was also obviously ber than that in the control group ( 0.39 ±0.01) ( Plt;0.05) .Meanwhile the SP-D levels in serumand lung tissue were higher in the COPD group than those in the LPS group ( Plt;0.05) . The levels of SP-D between serum and lung tissue were positively correlated in all three groups ( r=0.93, 0.94 and 0.93, respectively, Plt;0.01) .Conclusion Both the SP-D level in serum and in lung tissue increase significantly in COPD rats and correlate well each other, which suggests that SP-D may serve as a biomarker of COPD.
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.
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.
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】ObjectiveThere are two main functions of gastrointestinal tract, digestion and absorption, and barrier function. The latter has an important defensive effect, which keeps the body away from the invading and damaging of bacteria and endotoxin. It maintains the systemic homeostasis. Intestinal dysfunction would happen when body suffers from diseases or harmful stimulations. The more serious intestinal disorders would harm the intestinal protective mechanism, or intestinal barrier function, and bacterial/endotoxin translocation, of intestinal failure (IF) would ensue. This article provides a critical review of the evidence indicating that an increase in bacterial translocation is associated with sepsis, and even the multiple organ failure syndrome in critically ill patients. The intransit microorganisms play an essential role in the homeostasis of local and systemic immunity. MethodsAll studies published from 2000 to June 2005 about intestinal permeability, bacterial translocation, and systemic inflammatory response syndrome were located by search of PubMed. ResultsClinical and experimental studies investigating the correlation between bacterial translocation and systemic inflammatory response syndrome, associated with the damage of the gut barrier function . To keep the mucosal barrier function intact is one of the main issues in the prevention of bacterial translocation. This could be achieved by the adequate delivery of oxygen and nutrient supplementation to the gut. Enteral nutrition, probiotic can be a good choice. ConclusionWith a better understanding of the bacteriahost interactions in health and the alterations induced by critical illness, new therapies that improve the environment of both may lead to better recovery rates in intensive care unit patients.
Objective To study the protective effect of glutamine on the intestinal mucosal antioxidation in endotoxemic rats. Methods Twenty-eight male Wistar rats were randomly divided into three groups, group A:parenteral nutrition supplemented with glutamine, group B:TPN without glutamine,and group C:normal control. Endotoxemia was induced by continous intravenous infusion of lipopolysaccharide(LPS) at a dose of 2 mg/kg per day throughout the 5-day study period. The mucosal protein、DNA、ATP、SOD、MDA、GSH、sIgA were determined. Results The mucosal protein、DNA、ATP、SOD、GSH and sIgA content in endotoxic rats were markedly decreased, MDA was increased as compared with normal control(P＜0.05). The former indices in group A were improved and MDA content was decreased as compared with group B(P＜0.05). Conclusion Glutamine can improve gut energy metabolism, decrease the extent of mucosal injury of free radicals, and give an protective effect on the mucosal probably by increasing GSH.
Objective To observe the histopathologic features and expression patterns of tumor necrosis factor-alpha; （TNF-alpha;）, interleukin-1beta;（IL-1beta;） and Escherichia coli lipopolysaccharide (LPS) in the rat vitreous with LPS inducedendophthalmitis. Methods Wistar rats were randomly divided into saline control group (SC,136 rats）,endophthalmitis group （EO, 168 rats）and blank control group （BC,12 rats）.EO group received an intravitreal injection of 5 mu;l LPS; SC group received 5 mu;l sterile saline and no intervention for BC group.Six,12,24,48, and 72 hours,5 and 7 days after injection, intraocular inflammation were observed and the eyes and vitreous were collected for histopathological examination and measurement of TNF-alpha;, IL-1beta; and LPS expression. Results Severe inflammatory responses in the eyes were observed in EO group between six and 72 hours after LPS injection，ocular inflammation subsided seven days after LPS injection. In the vitreous, a peak neutrophil count was observed at 24 hours （1224.64plusmn;132.2） cells/eye that rapidly declined at 72 hours （342.25plusmn;47.7） cells/eye. The levels of TNF-alpha; and IL-1beta; in EO group were peaked at 24 hours with （996.18plusmn;89.45） and（5556plusmn;1440）pg/ L, respectively；Persisted at 48 hours and began to decline rapidly thereafter. Seven days after LPS injection, levels of TNF-alpha; and IL-1beta; returned to baseline with （22.16plusmn;5.84）and （73.7plusmn;18.7） pg/L, respectively. LPS concentration in EO group decrease rapidly at 72 hours with （11.03plusmn;3.41） ng and disappear on days 7 with (0.22plusmn;0.08) ng after LPS injection.Conclusions Massive neutrophils infiltration, high levels expression of TNF-alpha; and IL-1beta; and spontaneous elimination of bacterial elements in vitreous cavity were major pathologic characteristics in this experimental model. The expression patterns of TNF-alpha;,IL-1beta; were in accord with LPS clearance process.