Protective role of heat-shock protein 70 in gastric mucosal lesion induced by endotoxin in cirrhotic rats with portal hypertensive gastropathy

AIM: To investigate the protective role of heat-shock protein 70 (HSP70) in the pathogenesis of gastric mucosal damage in cirrhotic rats with portal hypertensive gastropathy (PHG).METHODS: The rat model of liver cirrhosis with PHG was established by injection with tetrachloride.The animals were divided into normal control group, PHG group, PHG+heat treatment group, PHG+BPI21 group and PHG+endotoxin groups.The endotoxin used in the experiment was at the dose of 3 mg/kg and endotoxin antagonist BPI21 was at the dose of 2 mg/kg.HSP70 was induced by pre-treating the animals with mild whole-body heating.The levels of HSP70 and tumor necrosis factor alpha (TNF-α) in the gastric mucosa were measured by ELISA.Furthermore, the pathological changes of the gastric mucosa were observed under microscope with HE staining.RESULTS: Compared with the normal control rats, the rats in PHG group showed obvious gastric pathological lesion, decrease in HSP70 production and increase in TNF-α level in the gastric mucosa, and increased endotoxin concentration in the plasma.Compared with PHG+endotoxin group, the gastric mucosal lesion in PHG+BPI21 group was significantly attenuated, accompanied by the increase in HSP70 production and decrease in TNF-α level in the gastric mucosa.Heat treatment increased HSP70 production and decreased TNF-α concentration in the PHG rats, thus attenuating the gastric mucosal damage.CONCLUSION: HSP70 alleviates the gastric mucosal lesion induced by endotoxin in cirrhotic rats with PHG and decreases the concentration of TNF-α in gastric mucosa, indicating a protective role of HSP70 in the pathogenesis of gastric mucosal damage in PHG.     

The protective effect of cistanche deserticola Y.C Ma. on thymocytes in septic rats

AIM: To study the protective effect of cistanche deserticola Y. C Ma. on thymocytes in septic rats. METHODS: Cecum ligation perforation (CLP) was used to induce sepsis. Treatment group was treated with cistanche deserticola Y. C Ma. （1.25 g·kg-1·d-1， ig） for 14 days before CLP. Animals were killed 12 h or 24 h after CLP and thmocytes were collected. The ratio of thmocyte apoptosis and mitochondrial membrane potential were determined by the flow cytometry. The ATP activity was detected by spectrophotography. RESULTS: The rate of thmocyte apoptosis significantly increased 12 h after CLP. The ATP activity decreased 24 h after CLP was significant. The extract of desert living cistanche effectively repressed the apoptosis of thymocytes and maintained the mitochondrial membrane potential. CONCLUSIONS: The extract of cistanche deserticola Y. C Ma. protects thymocytes against apoptosis induced by sepsis. Maintaining of mitochondrial membrane potential may be the protective mechanism.     

Effect of electro-acupuncture at Zusanli point on tumor necrosis factor-α induced-multiple organ dysfunction in rats with sepsis

AIM: To investigate the effect of electro-acupuncture (EA) at Zusanli (ST36) on proinflammatory factors induced-multiple organ dysfunction in rats with sepsis. METHODS: Sixty four male Wastar rats were used to develop the sepsis model by cecal ligation and puncture (CLP). The animals were randomly divided into 4 groups (n=16 in each group): CLP+EA (CLP/EA), CLP+sham EA (CLP/SEA), vagotomy+ CLP+SEA (VA/CLP/SEA) and vagotomy+CLP+EA (VA/CLP/EA). Zusanli point (ST36) was electroacupunctured with constant voltage (2-100 Hz, 2 mA for 0.5 h) 20 min after CLP surgery. Bilateral cervical vagotomies were performed in rats in VA/CL/SEA and VA/CLP/EA groups. Twelve hours after CLP, animals were sacrificed and liver, kidney and jejunum were harvested for evaluating the contents of tumor necrosis factor-α (TNF-α), myeloperoxidase (MPO) and diamine oxidase (DAO). The rate of water content (WCR) of the organs was determined. At the same time, the plasma levels of alanine aminotransferase (ALT) and creatinine (Cr) in each group were also detected. RESULTS: The levels of ALT and Cr in plasma, as well as TNF-α, MPO and WCR in organ tissues were markedly lower, and the activity of DAO in jejunum tissue was obviously higher than that in CLP/SEA group at 12 h after CLP (all P<0.05). The levels of ALT, Cr, TNF-α, MPO and WCR in VA/CLP/SEA group and VA/CLP/EA group were significantly higher, the activity of DAO was obviously lower than that in CLP/SEA group (all P<0.05). No statistical difference in all above measurements between VA/CLP/EA group and VA/CLP/SEA group was observed (all P>0.05). CONCLUSION: The results indicate that EA at Zusanli point obviously decreases the levels of TNF-α in liver, kidney and jejunum tissues after CLP, and alleviates the tissue edema and dysfunction of those organs. Vagotomy decreases or eliminates the effects of EA, suggesting that activation of cholinergic anti-inflammatory pathway is one of the main mechanisms to induce the effects of EA at ST36 on CLP sepsis.     

Effects of glutamine pretreatment on intestinal ischemia-reperfusion injury in rats

AIM：To determine the effects of glutamine (Gln) pretreatment on intestinal ischemia-reperfusion (I/R) injury in the rats. METHODS：Thirty male Wistar rats were randomly divided into 3 groups (n=10): sham group, I/R group and Gln pretreatment group. The rats in Gln pretreatment group were pretreated with 1 g·kg-1·d-1 Gln by orogastric route for 7 d, the rats in the other 2 groups were pretreated with normal saline. Intestinal I/R was induced by 30-min occlusion of the superior mesenteric artery followed by 24 h of reperfusion. After the operation, the plasma endotoxin, serum D-lactic acid, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured. The intestinal mucosal injury was observed with HE staining and evaluated using Chius scoring. RESULTS：Serum D-lactic acid, endotoxin level, MDA level and Chiu's score in I/R group were significantly higher than those in sham group and Gln group (all P<0.05). Serum SOD activity was significantly lower than that in sham group and Gln group (P<0.05). CONCLUSION：Glutamine has a protective effect on the intestines during ischemia-reperfusion injury. The mechanism may be related to oxidative stress response.     

Protective effect of ginkgolide B on CLP-induced septic mice

AIM: To explore the potential immunomodulatory effect and related mechanisms of ginkgolide B (GB), a known potent antagonist of platelet-activating factor receptor, on the pathological process of sepsis. METHODS: The experimental sepsis model was established by a standardized procedure of cecal ligation and puncture (CLP). GB treatment (10 μg/g) was given to the CLP mice 30 min before the surgical operation. The survival rate was observed every day for 3 weeks. The NO content in the serum was measured by Griess assay. The ROS level in the blood was determined by H₂DCFDA labeling and flow cytometry. The inflammatory cytokines in the serum were detected by the methods of cytometric bead array and ELISA. RESULTS: The thymus and spleen of the mice significantly atrophied, and the levels of NO, ROS, TNF-α, IL-1β, IL-6 and IL-10 in the blood were dramatically elevated 24 h after CLP. All the CLP mice died in 5 days. However, treatment with 10 μg/g of GB 30 min before CLP remarkably enhanced the indexes of thymus and spleen, inhibited the storm of inflammatory mediators and cytokines, and improved the survival rate. CONCLUSION: The protective effect of GB on CLP-induced experimental sepsis indicates that GB is a candidate of natural immunomodulator for treating sepsis.     

Protective effect of A. auricula-judae extracts on liver function in septic rats

AIM: To explore the effects of Auricularia (A.) auricula-judae extracts on the liver function in septic rats. METHODS: Forty male Wistar rats were randomly divided into control group, model group, A. auricula-judae polysaccharide group and A. auricula-judae crude extract group. Septic model was induced by the procedure of cecal ligation and puncture (CLP). Intragastric administration was performed every 8 h 3 days prior to CLP. The plasma levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), endotoxin(ET), tumor necrosis factor α(TNF-α), interleukin 6(IL-6) and IL-1β were detected 12 h after CLP. The specimens of the liver were collected to observe the pathological changes. The expression of NF-κB in the liver tissues was detected by the method of immunohistochemistry. RESULTS: Compared with the CLP rats, the intervention of A. auricula-judae polysaccharide and A. auricula-judae crude extract to the septic rats significantly decreased the serum levels of ALT, AST, ET, TNF-α, IL-1β and IL-6 (P<005). The pathological changes of the liver tissues in treatment groups were significantly attenuated compared with CLP group. CONCLUSION: A. auricula-judae polysaccharide and A. auricula-judae crude extract protect liver against sepsis-induced injury by inhibiting the systemic inflammatory response.     

The potential role of staphylococcal enterotoxin B in the early intestinal injury in postburn Staphylococcus aureus sepsis

AIM: To investigate the role of staphylococcal enterotoxin B (SEB) in early intestinal injury in scald rats with Staphylococcus aureus sepsis. METHODS: 86 male Wistar rats were randomly divided into four groups as folows: normal controls (n=10), scald control group(n=10), postburn sepsis group (n=50) and SEB monoclonal antibody (MAb) treatment group (n=16). Plasma samples were collected to determine SEB, endotoxin, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). RESULTS: After scald injury followed by Staphylococcus aureus challenge, the levels of SEB, TNF-α and IFN-γ in plasma were significantly higher than those of normal controls, peaking at 2-6 h (P<0.05 or P<0.01), while the intestinal diamine oxidase (DAO) activity declined constantly (P<0.05). It was shown that plasma SEB levels were significant negatively correlated with intestinal DAO activity (r=-0.4398, P=0.0170), and SEB MAb pretreatment could ameliorate the intestinal injury to certain extent. Moreover, Staphylococcus aureus challenge could increase the endotoxin levels in plasma and various tissues, which were attenuated by SEB MAb pretreatment. CONCLUSION: In postburn sepsis, SEB might be involved in the development of intestinal barrier dysfunction, which in turn resulting in gut-derived endotoxin translocation and aggravating the pathophysiologic changes caused by Staphylococcus aureus challenge.     

Therapeutic and protective effects of high-density lipoprotein of human plasma on endotoxemia in rats

AIM: To observe the therapeutic and protective effects of high-density lipoprotein (HDL) of human plasma on rat endotoxemia.METHODS: 26 rats were divided into 3 groups randomly,the treated group received bolus intravenous endotoxin (500 U/kg),followed by a bolus HDL (75 mg/kg) intravenously as their blood pressure (BP) decreased obviously.The control group just received bolus intravenous endotoxin without HDL.The protective group received bolus intravenous HDL before endotoxin challenge.BP,survival time,concentration of tumor necrosis factor(TNF) and levels of endotoxin in plasma were determined using radioimmunoassay and limulus lysate test.RESULTS: ①BP in control and treated groups all decreased obviously (P<0.01),and the extent of BP decrease in control group lowered more than that of treated group P<0.01),while no significant BP decrease was found in protective group (P>0.05).The survival time of treated and preventive rats were prolonged significantly than that of control group (P<0.01).②No obvious changes were found on the levels of endotoxin among the three groups (P>0.05).③On 3rd time point,the concentration of plasma TNFα decreased in treated and protective rats compared with that of control rats (P>0.05). CONCLUSION:HDL of human plasma could attenuate or inhibit the decrease in BP induced by endotoxin and prolong the survival time.These results indicated that HDL has therapeutic and protective effect on rat with endotoxemia.Inhibition of TNF release might be one of mechanisms.     

Changes of L-arginine,NOS/NO pathway in adventitia of rats with sepsis

AIM: In this study, we aimed to explore the alteration and pathophysiological significance of the L-arginine (L-Arg)/NOS/NO pathway in the adventitia of rats with sepsis. METHODS: Sepsis was induced by cecal ligation and puncture (CLP). Rat cardiac function was determined. NO generation, NOS activity and L-Arg transport were measured. The iNOS mRNA levels was determined by using RT-PCR. RESULTS: Cecal ligation and puncture induced severe sepsis with severe low glucose, high lacticemia and cardiac function inhibition. The iNOS activity was increased by 2.8-fold compared with controls (P<0.01) and the iNOS mRNA level was elevated-6-fold (P<0.01). The NO level in plasma and incubation media (incubation for 40 min) in the sepsis group was increased by 144% and 273% (both P<0.01), respectively. CONCLUSION: The results demonstrated that the L-Arg,NOS/NO pathway was activated in vascular adventitia of rats with sepsis shock. The aortic adventitia L-Arg/NOS/NO pathway might play an important role in the pathogenesis of sepsis and septic shock.     

Therapeutic effects of recombinant human growth hormone on rat sepsis

AIM:To investigate therapeutic effects of recombinant human growth hormone(rhGH) on rat sepsis and its possible mechanisms.METHODS:Mean arterial pressure (MAP), levels of plasma TNFα, IL-1β and endotoxin, leukocyte count and survival rate within 1 week were determined after E. coli injection among control group, sepsis group and sepsis+rhGH group.RESULTS:(1)rhGH diminished the decrease of MAP, reduced plasma endotoxin and TNFα levels and increased neutrophil ratio in total leukocytes in sepsis rat. rhGH increased survival rate within 1 week on sepsis rat. (2)No changes were found in IL-1β level among the three groups.CONCLUSION:rhGH showed desirable beneficial effects on rat sepsis, which may attribute to: improving circulatory function;maintaining intestinal mucosa barrier, attenuating bacteria/endotoxin translocation and inhibiting the production and release of TNFα.     

Assessment of myocardial dysfunction in septic rats with conventional echocardiography and tissue Doppler imaging

AIM To compare various conventional and tissue Doppler echocardiographic indexes to assess their accuracy to detect left ventricular (LV) intrinsic systolic and diastolic dysfunction in septic rats. METHODS Twenty-two SD rats were randomly divided into 2 groups: sham group and sepsis group, with 11 rats in each group. A model of sepsis was established by cecal ligation and puncture (CLP). Serum tumor necrosis factor-α (TNF-α) level, and myocardial intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression were determined by ELISA and Western blot. The LV systolic and diastolic functions were analyzed by isolated heart Langendorff perfusion technique, conventional echocardiography and tissue Doppler imaging. RESULTS Compared with sham group, the serum TNF-α level, and LV ICAM-1 and VCAM-1 expression were increased significantly, while LV ±dp/dt_max, stroke volume and LV end-diastolic volume were markedly decreased at 6 h after CLP. Moreover, compared with sham group, mitral inflow peak E and A wave velocities as well as early-diastolic peak velocities (E' wave) and late-diastolic peak velocities (A' wave) of the mitral annulus were reduced significantly in sepsis group at 6 h after CLP. In contrast, no significant difference in LV ejection fraction and E/E' ratio between sham group and sepsis group was observed. Further investigation revealed that peak E' wave and A' wave velocities were positively correlated with -dp/dt_max (r=0.460 and r=0.520, P<0.05). CONCLUSION At the early stage of sepsis, tissue Doppler echocardiography is a useful technique to assess LV diastolic dysfunction, and peak E' and A' wave velocities may be the sensitive indexes to detect LV intrinsic diastolic dysfunction.     

Dynamic changes of mouse cardiac functions in early stage of sepsis induced by CLP

AIM: To detect the changes of cardiac functions of septic mice in the early stage of sepsis. METHODS: Health male Kunming mice were used in the study. The techniques of 2D, M-mode and Doppler echocardiography were applied to evaluate the cardiac functions before cecal ligation and puncture(CLP) as baseline and at time points of 12 h, 24 h, 36 h, 48 h and 168 h after CLP. The mice survived for 168 h(7 d) were considered as survivals. RESULTS: Compared to the baseline at the time point of 24 h after CLP, the blood volumes of heart return decreased significantly in the early stage of sepsis induced by CLP. LVEDV reduced by 46%. Notable compensatory responses of the hearts in septic mice were observed, especially the systolic functions, in which LVEF and LVFS increased by 27% and 39%, respectively. However, the compensatory responses of diastolic function were weaker than the systoles. E/A ratio and EDT decreased by 30% and 25% respectively at the time point of 24 h. CONCLUSION: The strong compensatory cardiac functions are one of the factors for supporting the septic animal to survive. Protection of the cardiac functions especially the diastoles is important in the treatment of septic patients.     

Hemodynamic changes of abdominal organs in the early stage of septic mice induced by cecal ligation and puncture

AIM: To characterize the hemoperfusion of abdominal organs in the early stage of sepsis in mice. METHODS: Health male Kunming mice were used in the study (n=100). The techniques of 2D, M-mode and pulse-wave Doppler were applied to evaluate the systolic functions of the heart and the blood flow of abdominal aorta, right renal artery and portal vein before cecal ligation and puncture (CLP) as the baseline and at the time points of 12 h, 24 h, 36 h, 48 h and 60 h after CLP. The mice survived for 7 d were considered as survivals. All data were compared with the baseline values.RESULTS: The cardiac output of the CLP mice remained in normal or hyperdynamic levels in the early stage of sepsis. Compensatory responses of systolic functions were observed. The levels of blood flow in abdominal aorta were increased first and then decreased. Resistent index (RI) and pulsatility index (PI) of abdominal aorta began to increase at the time point of 24 h. Blood flow of right renal artery showed a significant decline from the beginning to the end of our observation. No significant difference of the right arteriorenal RI and PI was observed. Portal venous flow increased significantly at 12 h, and decreased at 24 h after CLP. Congestion index of the portal vein was distinctly increased from 12 h to the end of the observation. CONCLUSION: The hemodynamics of abdominal organs in early stage of septic mice shows specific changes, indicating an important role in evaluating the mechanism of sepsis.     

PI3K/Akt signaling pathway regulates autophagy induced by acute kidney injury in septic rats

AIM：To investigate the autophagy induced by sepsis and acute kidney injury, and the regulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in this process. METHODS：The rats were subjected to cecal ligation and puncture (CLP) or sham operation. Histopathologic changes of the renal tissues were examined by HE staining. Blood urea nitrogen (BUN) and serum creatinine (SCr) were measured by chemical colorimetry. The protein expression of microtubule-associated protein light chain 3 I/II (LC3 I/II), beclin-1 and p-Akt at different time points after CLP was detected by Western blotting. In vitro, human proximal tubular epithelial cell line HK-2 were treated with LPS to induce autophagy. The protein expression of LC3 I/II and p-Akt in the HK-2 cells after LPS treatment at different time points and different concentrations was detected by Western blotting. These molecules in HK-2 cells and apoptosis of HK-2 cells treated with LPS plus PI3K inhibitor or Akt inhibitor were also detected. RESULTS：Compared with sham group, the severe changes of renal histopathological injuries in CLP groups were observed, the levels of BUN and SCr in CLP groups were significantly increased. LC3 I/II, beclin-1 and phosphorylation of Akt gradually increased after CLP. After treatment with LPS, the expression of p-Akt (308) in the HK-2 cells gradually increased in a dose- and time-dependent fashion. The expression of beclin-1 and p-Akt (472) reached a peak at 8 h or 10 mg/L LPS treatment. Treatment with PI3K or Akt inhibitor down-regulated the expression of LC3 and promoted the apoptosis of HK-2 cells. CONCLUSION：Autophagy in the kidney is induced by sepsis and acute kidney injury. PI3/Akt signaling pathway may be involved in this process.     

Effects of aminoguanidine on endotoxin-induced acute lung injury in rabbits

AIM: To observe the effect of aminoguanidine (AG) on hemodynamics and lung capillary permeability in acute lung injury (ALI) in rabbits. METHODS:24 rabbits were equally divided into four groups: saline group, endotoxin group, AG group and AG plus endotoxin group. In AG plus endotoxin group, endotoxin was injected to animals to make an ALI model, 25mg/kg AG was injected following that and let this sustain 3 hours. Meanwhile, mean arterial pressure (MAP), mean pulmonary arterial pressures (MPAP) and blood gas analyses were observed during this period. At the end of the experiment, broncho-alveolus lavage was performed, pathologic samples were treated routinely and lung wet weight/dry weight ratio was calculated. RESULTS:After endotoxin injection, MAP and arterial oxygen pressure (PaO₂) decreased, and MPAP increased significantly. The injection of AG had little effect on MAP, but AG could markedly decrease MPAP and increase PaO₂. Cell count in broncho-alveolus lavage fluid (BALF) was less in AG plus endotoxin group than in endotoxin group. Although AG did not affect total protein in BALF, low molecular weight proteins decreased in AG plus endotoxin group by the assay of electrophoresis. Tissue wet weight/dry weight ratio also decreased in this group. Pathologic study showed that there were fewer inflammatory cells and less lung edema in AG plus endotoxin group. CONCLUSION:AG could improve hemodynamics status and attenuate acute lung injury induced by endotoxin in rabbits.     

Berberine inhibits enterocyte apoptosis in septic mice

AIM: To observe the effects of berberine (Ber) on enterocyte apoptosis in septic mice and its possible mechanism. METHODS: Male C57BL/6 mice (8~10 weeks old) were randomly divided into sham group, cecal ligation and puncture (CLP) group, CLP+Ber group and sham+Ber group. The mice in CLP group underwent CLP ope-ration, and the mice in sham groups suffered a similar operation except the ligation and puncture. After the sham or CLP operation, the mice were administered intragastrically with distilled water or berberine (50 mg/kg) within 2 h. After 20 h, the mice were killed with excess pentobarbital sodium and the ileum tissues were removed. The histological changes of the intestine were observed and the enterocyte apoptosis was examined by determining the protein level of cleaved caspase-3. Furthermore, mitochondrial Bax, cytoplasm cytochrome C (Cyt C) and the total proteins of Bcl-2, Fas, FasL and Fas-associated protein with death domain (FADD) were examined by Western blot. The mRNA expression of tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) was measured by real-time PCR. RESULTS: The extensive ileum injuries, including remarkably increased leukocytes and necrosis of intestinal villus were observed 20 h after CLP. In CLP group, the protein levels of cleaved caspase-3, cytoplasm Cyt C, as well as Fas, FasL were significantly increased, but the Bcl-2 level was decreased. Bax translocation into mitochondria was promoted. However, FADD was not changed significantly. The mRNA expression of TH and DBH was also increased sharply in CLP group. On the contrary, treatment with berberine made a considerable alleviating alteration in the ileum of the septic mice.CONCLUSION: Treatment with berberine provides protective effects on intestinal injury in septic mice by reducing enterocyte apoptosis, and its possible mechanism may be involved in the inhibition of the endogenous and exogenous apoptosis pathways.     

Dynamic expression of CD30 on peripheral blood lymphocytes in mice after a cecal ligation and puncture

AIM: To investigate the details of Th2 cell differentiation in septic mice. METHODS: Experimental septic mice were induced by cecal ligation and puncture (CLP). The exression of CD30 on CD4⁺T cells at different time after CLP were estimated by flow cytometry following three-color immunofluorescent staining.RESULTS: CD30 expression on CD4⁺T cell was different at each time point. The highest expression was showed at 38 h after CLP and declined later, which matched the changes in mortality of the animals. CONCLUSION: During sepsis, differentiation of Th2 cell changed with the development of sepsis and might be associated with the severity of the disease.     

Heme oxygenase-1 protects renal function in septic rats via influencing expression of thrombomodulin

AIM: To investigate the protective effect of heme oxygenase-1 (HO-1) on the kidney of septic rats and the influence of HO-1 on the expression of thrombomodulin (TM) in the kidney. METHODS: Sepsis in rats was developed with cecal ligation and puncture (CLP). The septic rats were randomly divided into sham group, CLP group, CLP+HO-1 inducer group and CLP+HO-1 inhibitor group (n=18). The plasma levels of creatinine (Cr), cystatin-C (Cys-C), carboxyhemoglobin (COHb), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and TM, and the changes of prothrombin time (PT) and activated partial thromboplastin time (APTT) in each group were measured. Histopathological examination was performed in the kidney. The expression of TM in the kidney tissue was detected by Western blot. RESULTS: Compared with sham group, significantly elevated plasma levels of Cr, Cys-C, TNF-α, IL-1β and TM (P<0.05), shortened PT and APTT (P<0.05), significantly increased microthrombus formation, and lowered TM expression in the kidney (P<0.05) of CLP group were observed. The administration of hemin lowered the plasma levels of Cr, Cys-C, TNF-α, IL-1β and TM (P<0.05), prolonged PT and APTT (P<0.05), attenuated microthrombus formation, and up-regulated the expression of TM in the kidney (P<0.05). In contrast, ZnPP had the opposite effects. CONCLUSION: HO-1 increases the expression of TM in the kidney and exerts anticoagulatory and antiinflammatory effects, thereby improving renal function in the septic rats.     

Mechanisms for a decrease in mortality of LPS-challenged mice by rhynchophylline

AIM: To observe effect of rhynchophylline （Rhy） on mortality and organ injury in endotoxemic mice and further investigate the mechanisms of its actions. METHODS: Male mice were randomly assigned into control, LPS, Rhy +LPS and Rhy group, and injected subcutaneously with normal saline (0.05 mL/10 g), or rhynchophylline once a day for 3 d, 1 h after subcutaneously treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally. Survival rate was recorded every 12 h for 6 d. In another experiment, 12 h after LPS injection, the left lung and intestine tissue sections were prepared for histological analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D),the serum was collected to detect the concentrations of alanine aminotransferase（ALT）, aspartate aminotransferase (AST ), bloodureanitrogen (BUN) and creatinine (Cr). In addition, the concentrations of tumor necrosis factor-α (TNF-α), interleukin-1β(IL-1β) and interleukin-10 (IL-10) in serum at 2 h after LPS challenge were detected by enzyme-linked immunosorbent assay. The concentration of NO in serum at 8 h was detected by enzymic method. The effect of Rhy on survival rate of mice subjected to cecal ligation and puncture (CLP) was also observed. RESULTS: Mortality of mice challenged with LPS alone was higher significantly than that in control at 24 h after LPS challenge, pretreated with Rhy at a dose of 8 or 16 mg/kg increased markedly the survival rate of LPS-challenged mice. However, Rhy at a dose of 8 mg/kg significantly increased mortality of mice subjected to CLP. In the histological analysis, severe inflammation was observed both in the lung and intestine tissues in the LPS group. LPS elevated lung W/D, the levels of ALT, AST, BUN, Cr, TNF-α, IL-1β, IL-10 and NO in serum. Pretreatment with Rhy had no obvious improvement in the lung and intestine tissue injury, and no significant depression in the lung W/D and the serum levels of ALT, AST, BUN, Cr, IL-1β, IL-10 and NO, but decreased the level of TNF-α in serum significantly in LPS -treated mice. CONCLUSION: Pretreatment with Rhy reduces the mortality in endotoxemic mice, but not decrease the mortality of mice challenged with CLP, at least in part, through inhibiting the synthesis and secretion of TNF-α.     

Protective effects of glutamine pretreatment on occludin protein in rats with intestinal ischemia-reperfusion injury

AIM: To determine the effects of glutamine(Gln) pretreatment on occludin protein in the rats with intestinal ischemia-reperfusion(I/R) injury. METHODS: Male Wistar rats(n=30) were randomly divided into 3 groups(n=10):sham group, I/R group and Gln pretreatment group. The rats in Gln pretreatment group were pretreated with Gln at dose of 1 g·kg^-1·d^-1 by orogastric route for 7 d, and those in the other 2 groups were pretreated with the same volume of normal saline. Intestinal I/R was induced by 30-min occlusion of the superior mesenteric artery followed by 24 h of reperfusion. After the operation, the levels of IL-10, IL-2, TNF-α, SOD and MDA were measured. The occludin protein was determined by the methods of immunohistochemistry and Western blotting. RESULTS: The occludin protein level in I/R group was significantly lower than that in sham group and Gln group(P<0.05). The levels of MDA and TNF-α in I/R group were significantly higher than those in sham group and Gln group(P<0.05). The levels of SOD, IL-10 and IL-2 in I/R group were significantly lower than those in sham group and Gln group(P<0.05). CONCLUSION: Glutamine has a protective effect on occludin protein in intestinal ischemia-reperfusion injury. The mechanism may be rela-ted to oxidative stress response and inflammatory inhibition.