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.
Objective To investigate the effects of expression of TNFα mRNA on glucose uptake in both the liver and skeletal muscle after endotoxemia. Methods In the mice with intraperitoneal injection of lipopolysaccharide (LPS), the changes of TNFα level of plasma and uptake of 2-deoxyglucose (2-DG) in the isolated soleus muscle and hepatic tissues were determined, then the reinstatement of glucose uptake by injecting TNF-McAb for 3 days was also observed. In addition, changes of TNFα mRNA expression of liver were evaluated. Results The expression of TNFα mRNA in the liver showed markedly increased in the first 3 hours post endotoxemia and remaind high for 3 days, and the plasma TNFα level paralleled with TNFα mRNA expression of liver also was elevated. The basal uptake of 2-DG both in muscle and liver were markedly increased, but the stimulated 2-DG uptake with insulin was greatly reduced as compared with the control. In addition, these abnormalities of 2-DG uptake can be partially corrected by neutralization of the circulatory TNFα by administration of TNF-McAb. Conclusion The disorders of glucose uptake of the liver and the muscle due to the overexpression of TNFα mRNA and elevated circulatory TNFα level may be the mechanism of insulin resistance after endotoxemia.
ObjectiveTo investigate the change of renal endothelin (ET) excretion and its relation to renal dysfunctions in obstructive jaundice.MethodsSixty male Wistar rats were randomized into two groups, the common bile ducts were ligated to establish the model of obstructive jaundice in experimental group, and only sham operation was done in control group. Ten rats were taken from each group at 5, 10 and 15 days respectively after operation, renal functions were evaluated by paminohippuric acid clearance (CPAH), inulin clearance (CIN) and fractional sodium excretion (FENa+); furthermore, plasma endotoxin (EX) level was determined, and ET1 contents in renal arterial plasma, renal venous plasma and renal tissue were detected. ResultsOnly FENa+ was significantly increased at the 5th day in experimental group; since the 10th day, all the three renal functional parameters gradually decreased, and FENa+ was significantly lower than that in control group at 15th day (P＜0.01 vs control). ②The plasma EX sustained at significantly higher levels after operation in experimental group (P＜0.01 vs control). ③The renal arterial plasma ET1 was significantly decreased, while the contents in renal venous plasma and renal tissue were significantly increased after operation in experimental group (P＜0.01 vs control). ④There were positive correlation between plasma EX and renal ET1 content, negative correlation between renal ET1 content and CPAH/CIN, and positive correlation between renal ET1 content and FENa+ (P＜0.01).ConclusionThe increased excretion of renal ET stimulated by endotoxemia may play an important role in the renal dysfunctions in obstructive jaundice.
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 To compare the vasoactive effects of norepinephrine( NE) and dopamine of different doses on isolated rabbit pulmonary and systemic arteries in septic shock. Methods Six paired pulmonary and systemic arterial rings were prepared fromsix rabbits, and matched randomly assigned into a normal group and a LPS group. The assigned groups were intervened by different doses of NE. Another six paired pulmonary and systemic arterial rings were prepared from another six rabbits. They were assigned to different groups as above and intervened by different doses of dopamine. The LPS groups were pre-incubated in RPMI mediumsupplemented with4 μg/mL LPS to simulate septic shock. The tension of arterial rings was measured and its response to NE and dopamine were studied. Results ( 1) In the normal groups, the contraction of the systemic arteries was ber than the pulmonary arteries in response to low,middle dose of NE, and high dose of dopamine ( all P lt; 0. 05) , and which was weaker in response to middle dose of dopamine and similar in response to high dose of NE( P gt;0. 05) . Both the pulmonary and systemic arteriesrelaxed in response to low dose of dopamine. ( 2) After LPS pre-incubation, the contraction of the systemic arteries was weaker than the pulmonary arteries in response to low dose of dopamine ( P lt;0. 05) , and which was similar in response to low,middle and high dose of NE, and middle, high dose of dopamine. ( 3) Comparing the LPS groups with the normal groups, the contraction in response to middle dose of dopamine increased in the systemic arteries and dreased in the pulmonary arteries ( P lt;0. 05) . Conclusions In septic shock, the vasoactive effect of different doses of NE is not different between pulmonary and systemic arteries. But middle dose of dopamine can increase the contraction of systemic arteries and decrease the contraction of pulmonary arteries.
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.
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.
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 examine the role of recombinant interleukin-10 (IL-10) and the therapeutic effect of endotoxin-induced uveitis (EIU) in rats.Methods Fifty-six male Wistar rats were randomized into three groups. IL-10 treatment group and positive control group had 24 rats respectively, and the normal control group had eight rats. Endotoxin-induced uveitis (EIU) is an established animal model of acute ocular inflammation induced by LPS intravenous injection (1 mu;g/kg). The onset times and signs were observed and the clinical scores were recorded. The blood samples and the aqueous humor samples of right eye were collected separately before the rats were sacrificed at fourth hour, 24th hour and third day after LPS injection. The enzyme-linked immunosorbent assay was used to measure tumor necrosis factor (TNF) alpha;,IL-6, and IL-10 levels in the serum and aqueous humor. The left eyes were used for pathological examination and pathological grading. Results The symptoms of uveitis were appeared in all 24 rats in the positive group. The average onset time was (3.81plusmn;1.05) hours, the average clinical score was 3.67plusmn;1.97. The mild manifestations of uveitis were also appeared in all of the rats in treatment group. The average onset time was (5.63plusmn;1.02) hours, the average clinical score was 2.00plusmn;1.25. The average onset time in treatment group was postponed compared with the rats of positive group (t=4.95, P=0.000). The clinical scores (t=3.50, P=0.00) and the pathological grades (t=3.28, P=0.00) in treatment group were lower than those of positive group. There were not signs or pathologic changes in all the eight rats in the negative control group. The serum and aqueous humor levels of TNF-alpha; and IL-6 in the rats of positive group were higher than those of the treatment group and control group (F=15.34, 57.65, 67.59, 8.42; P=0.00). The serum and aqueous humor levels of IL-10 in the rats of treatment group were higher than those of the positive group and the control group (F=17.84,7.76; P=0.00). There were positive correlations between the level of aqueous humor TNF-alpha;, serum and aqueous humor levels of IL-6 and the disease severity (reye＝0.58, 0.31,0.81, rpath＝0.56, 0.31, 0.74; P＜0.05). The negative correlations were presented between the serum levels of IL-10 with the disease severity (r=-0.54,-0.55; P=0.00). There were negative correlations between the serum and aqueous humor levels of TNF-alpha; and IL-6 and the onset time of the disease (r＝-0.47,-0.59,-0.77,-0.36; P＜0.05) as well. Conclusions These findings bly suggest that suppressive IL-10 is a potent candidate for the prevention of TNF-alpha; and IL-6 in uveitis and could be applied as a novel immunoregulatory agent to control EIU.