L-arginine administration ameliorates serum and pulmonary cytokine response after gut ischemia-reperfusion in immature rats

AIM: Small intestinal ischemia-reperfusion (IR) has been demonstrated to result in both local mucosal injury and systemic injuries. The exact role of nitric oxide (NO) in intestinal IR is unclear. We propose that NO and some other cytokines change in the reperfusion period and these changes are associated with lung injury. The aim of this study was to determine the effect of supplementing NO substrate, L-arginine (L-arg), on serum and pulmonary cytokine production during small intestinal IR in immature rats. METHODS: Immature rats underwent 60 min. of superior mesenteric artery occlusion followed by 90 min of reperfusion. L-arg (250 mg/kg) was given intravenously to the experimental group (IR+L-arg) which received L-arg after 45 min of intestinal ischemia. Serum and lung endothelin-1 (ET-1), NO, malondialdehyde (MDA), and tumor necrosis factor a (TNFα) were measured. Sham operation (SHAM) and intestinal IR (IR) groups were performed as control. The lavage fluid of the lung was collected by bronchoalveolar lavage (BAL) and white blood cells and polymorphonuclear cells (PMNs) were immediately counted to identify lung damage. RESULTS: When L-arg was given during small intestinal IR, serum NO concentration increased significantly in IR+L-arg group (162.17±42.93 μmol/L) when compared with IR group (87.57±23.17 μmol/L, t=3.190, P= 0.008 <0.01). Serum MDA reduced significantly in IR+L-arg group (8.93±1.50 nmol/L) when compared with SHAM (23.78±7.81 nmol/L, t= 3.243, P= 0.007<0.01) and IR (25.54±9.32 nmol/L, t= 3.421, P= 0.006<0.01). ET-1 level in lung tissues was significantly lower in IR+L-arg group (13.81±7.84 pg/mL) than that in SHAM (35.52±10.82 pg/mL, t= 2,571, P= 0,03<0.05) and IR (50.83±22.05 pg/mL, t= 3.025, P= 0.009<0.01) groups. MDA contents in lung tissues were significantly lower in IR+L-arg group (10.73±1.99 nmol/L) than in SHAM (16.62±2.28 nmol/L, t= 3.280, P = 0.007<0.01) and IR (21.90±4.82 nmol/L, t= 3.322, P= 0.007<0.01) groups. Serum and lung TNFα concentrations were not significantly different in three groups. NO contents in lung homogenates and white blood cell counts in BAL had no significant difference in three groups; but the percentage of PMNs in BAL was 13.50±8.92, 33.20±16.59, and 22.50±6.09 in SHAM, IR, and IR+L-arg groups, respectively. CONCLUSION: Small intestinal IR induced increases of pulmonary neutrophil infiltration in immature rats. Neutrophil infiltration in lung tissues was reduced by L-arg administration but remained higher than in SHAM group. L-arg administration during intestinal IR enhances serum NO production, reduces serum MDA and lung ET-1 and MDA levels, resulting in the improvement of systemic endothelial function. L-arg supplementation before reperfusion may act as a useful clinical adjunct in the management of intestinal IR, thus preventing the development of adult respiratory distress syndrome, even multiple organ dysfunction syndrome (MODS).     

Protective effect of inducible nitric oxide synthase inhibitor on pancreas transplantation in rats

AIM： To investigate the effect of inducible nitric oxide synthase inhibitor, aminoguanidine, on pancreas transplantation in rats. METHODS： A model of pancreas transplantation was established in rats. Streptozotocin-induced diabetic male Wistar rats were randomly assigned to sham-operation control group （n = 6）, transplant control group （n = 6）, and aminoguanidine （AG） treatment group （n = 18）. In the AG group, aminoguanidine was added to intravascular infusion as the onset of reperfusion at the dose of 60 mg/kg, 80 mg/kg, 100 mg/kg body weight, respectively. Serum nitric oxide （NO） level, blood sugar and amylase activity were detected. Nitric oxide synthase （NOS） test kit was used to detect the pancreas cNOS and inducible NOS （iNOS） activity. Pancreas sections stained with HE and immunohistochemistry were evaluated under a light microscope. RESULTS： As compared with the transplant control group, the serum NO level and amylase activity decreased obviously and the evidence for pancreas injury was much less in the AG group. The AG （80 mg/kg body weight） group showed the most significant difference in NO and amylase （NO： 66.0 ± 16.6 vs 192.3 ± 60.0, P 〈 0.01 and amylase： 1426 ± 177 vs 4477± 630, P 〈 0.01）. The expression and activity of tissue iNOS, and blood sugar in the AG （80 mg/kg body weight） group were much lower than those in the transplant control group （iNOS： 2.01 ± 0.23 vs 26.59 ±5.78, P 〈 0.01 and blood sugar： 14.2 ±0.9 vs 16.8 ± 1.1, P 〈 0.01）. CONCLUSION： Selective iNOS inhibitor, aminoguanidine as a free radical, has a protective effect on pancreas transplantation in rats by inhibiting NO and reducing its toxicity.     

Pyrrolidine dithiocarbamate reduces ischemia-reperfusion injury of the small intestine

AIM: To evaluate whether pyrrolidine dithiocarbamate (PDTC), an enhancer of HO production, attenuates intestinal IR injury. METHODS: Eighteen male rats were randomly allocated into three groups: (a) sham; (b) IR, consisting of 30 min of intestinal ischemia, followed by 2-h period of reperfusion; and (c) PDTC treatment before IR. Intestinal microvascular perfusion (IMP) was monitored continuously by laser Doppler flowmetry. At the end of the reperfusion, serum samples for lactate dehydrogenase (LDH) levels and biopsies of ileum were obtained. HO activity in the ileum was assessed at the end of the reperfusion period. RESULTS: At the end of the reperfusion in the IR group, IMP recovered partially to 42.5% of baseline (P<0.05 vs sham), whereas PDTC improved IMP to 67.3% of baseline (P<0.01 vs IR). There was a twofold increase in HO activity in PDTC group (2 062.66±106.11) as compared to IR (842.3±85.12) (P<0.001). LDH was significantly reduced (P<0.001) in PDTC group (585.6±102.4) as compared to IR group (1 973.8±306.5). Histological examination showed that the ileal mucosa was significantly less injured in PDTC group as compared with IR group. CONCLUSION: Our study demonstrates that PDTC improves the IMP and attenuates IR injury of the intestine possibly via HO production. Additional studies are warranted to evaluate the clinical efficacy of PDTC in the prevention of IR injury of the small intestine.     

Ischemic preconditioning ameliorates intestinal injury induced by ischemia-reperfusion in rats

AIM: To evaluate preventative effects of ischemic preconditioning(IP) in a rat model of intestinal injury induced by ischemia-reperfusion(IR).METHODS: Male Sprague-Dawley rats(250-300 g) were fasted for 24 h with free access to water prior to the operation.Eighteen rats were randomly divided into three experimental groups: S group(n = 6),rats were subjected to isolation of the superior mesenteric artery(SMA) for 40 min,then the abdomen was closed; IRgroup(n = 6),rats were subjected to clamping the SMA 40 min,and the abdomen was closed followed by a 4-h reperfusion; IP group(n = 6) rats underwent three cycles of 5 min ischemia and 5 min reperfusion,then clamping of the SMA for 40 min,then the abdomen was closed and a 4-h reperfusion followed.All animals were euthanized by barbiturate overdose(150 mg/kg pentobarbital sodium,i.v.) for tissue collection,and the SMA was isolated via median abdominal incision.Intestinal histologic injury was observed.Malondialdehyde(MDA),myeloperoxidase(MPO) and tumor necrosis factor(TNF)-a concentrations in intestinal tissue were measured.Intercellular adhesion molecule(ICAM)-1 and vascular cell adhesion molecule(VCAM)-1 expression,as well as nuclear factor(NF)-κB activity and expression in intestinal tissue were also determined.RESULTS: Compared with the IR group,IP reduced IR-induced histologic injury of the intestine in rats(2.00 ± 0.71 vs 3.60 ± 0.84,P 0.05).IP significantly inhibited the increase in MDA content(5.6 ± 0.15 μmol/L vs 6.84 ± 0.18 μmol/L,P 0.01),MPO activity(0.13 ± 0.01 U/L vs 0.24 ± 0.01 U/L,P 0.01),and TNF-a levels(7.79 ± 2.35 pg/m L vs 10.87 ± 2.48 pg/m L,P 0.05) in the intestinal tissue of rats.IP also markedly ameliorated the increase in ICAM-1(204.67 ± 53.27 vs 353.33 ± 45.19,P 0.05) and VCAM-1(256.67 ± 58.59 vs 377.33 ± 41.42,P 0.05) protein expression in the intestinal tissues.Additionally,IP remarkably decreased NF-κB activity(0.48 ± 0.16 vs 0.76 ± 0.22,P 0.05) and protein expression(320.23 ± 38.16 vs 520.76 ± 40.53,P 0.01) in rat intestinal tissue.CONCLUSION: IP may protect against IR-induced intestinal injury by attenuation of the neutrophilendothelial adhesion cascade via reducing ICAM-1 and VCAM-1 expression and TNF-a-induced NF-κB signaling pathway activity.     

Protective effect of Astragalus membranaceus on intestinal mucosa reperfusion injury after hemorrhagic shock in rats

AIM: To study the protective effect of Astragalus membranaceus on intestinal mucosa reperfusion injury and its mechanism after hemorrhagic shock in rats. METHODS: A total of 32 SD rats were randomly divided into four groups (n = 8, each group): normal group, model group, low dosage group (treated with 10 g/kg Astragalus membranaceus) and high dosage group (treated with 20 g/kg Astragalus membranaceus). The model of hemorrhagic shock for 60 min and reperfusion for 90 min was established. Therapeutic solution (3 mL) was administrated before reperfusion. At the end of the study, the observed intestinal pathology was analyzed. The blood concentrations of lactic acid (LD), nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) in intestinal mucosa were determined. RESULTS: The intestinal mucosa pathology showed severe damage in model group and low dosage group, slight damage in high dosage group and no obvious damage in normal group. The Chiu's score in low dose group and high dose group was significantly lower than that in model group. The content of MDA in model group was higher than that in low and high dose groups, while that in high dose group was almost the same as in normal group. The activity of SOD and GSH-PX was the lowest in model group and significantly higher in high dose group than in normal and low dose groups. The concentrations of LD and ET-1 in model group were the highest. The concentrations of NO in model group and low dose group were significantly lower than those in high dose group and normal group. CONCLUSION: High dose Astragalus membranaeus has much better protective effect on hemorrhagic shock-reperfusion injury of intestinal mucosa than low dose Astragalus membranaceus. The mechanism may be that Astragalus membranaceus can improve antioxidative effect and regulate NO/ET level during hemorrhagic reperfusion.     

Impact of intestinal ischemia/reperfusion and lymph drainage on distant organs in rats

AIM:To investigate the impact of intestinal ischemia/reperfusion(I/R) injury and lymph drainage on distant organs in rats.METHODS:Thirty-two Sprague-Dawley male rats,weighing 280-320 g,were randomly divided into blank,sham,I/R,and ischemia/reperfusion and drainage(I/R + D) groups(n = 8).All rats were subjected to 60 min ischemia by clamping the superior mesenteric artery,followed by 120 min reperfusion.The rats in the I/R + D group received intestinal lymph drainage for 180 min.In the sham group,the abdominal cavity was opened for 180 min,but the rats received no treatment.The blank group served as a normal and untreated control.A chromogenic limulus assay kit was used for quantita-tive detection of serum endotoxin.The serum concentrations of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-1β,soluble cell adhesion molecules(sICAM-1),and high mobility group protein box 1(HMGB1) were determined with an enzyme-linked immunosorbent assay kit.Histological evaluations of the intestine,liver,kidney,and lung were performed by hematoxylin and eosin staining and immunohistochemistry.HMGB1 protein expression was assayed by western blot analysis.RESULTS:The serum levels of endotoxin and HMGB1 in the I/R and I/R + D groups were significantly higher than those in the sham group(endotoxin,I/R and I/R + D vs sham:0.033 ± 0.004 EU/mL,0.024 ± 0.003 EU/mL vs 0.017 ± 0.009 EU/mL,respectively,P 0.05;HMGB1,I/R and I/R + D vs sham:5.473 ± 0.963 EU/mL,4.906 ± 0.552 EU/mL vs 0.476 ± 0.406 EU/mL,respectively,P 0.05).In addition,endotoxin and HMGB1 were significantly lower in the I/R + D group compared to the I/R group(P 0.05).The serum inflammatory factors IL-6,IL-1β,and sICAM-1 in the I/R and I/R + D groups were significantly higher than those in the sham group(IL-6,I/R and I/R + D vs sham:41.773 ± 9.753 pg/mL,19.204 ± 4.136 pg/mL vs 11.566 ± 2.973 pg/mL,respectively,P 0.05;IL-1β,I/R and I/R + D vs sham:144.646 ± 29.378 pg/mL,65.829 ± 10.888 pg/mL vs 38.178 ± 7.157 pg/mL,respectively,P 0.05;sICAM-1,I/R and I/R + D vs sham:97.360 ± 12.714 ng/mL,48.401 ± 6.547 ng/mL vs 33.073 ± 5.957 ng/mL,respectively;P 0.05).The serum TNF-α in the I/R group were significantly higher than in the sham group(45.863 ± 11.553 pg/mL vs 18.863 ± 6.679 pg/mL,respectively,P 0.05).These factors were significantly lower in the I/R + D group compared to the I/R group(P 0.05).The HMGB1 immunohistochemical staining results showed no staining or apparent injury in the blank group,and slight staining at the top of the microvillus was detected in the sham group.In the I/R group,both the top of villi and the basement membrane were stained for HMGB1 in most areas,and injury in the I/R + D group was less than that in the I/R group.HMGB1 expression in the liver,kidney,and lung of rats in the I/R + D group was significantly lower than the rats in the I/R group(P 0.05).CONCLUSION:Lymph drainage could block the "gutlymph" pathway,improve intestinal barrier function,and attenuate distant organ injury incurred by intestinal I/R.     

Effects of ischemic preconditioning on cyclinD1 expression during early ischemic reperfusion in rats

AIM: To observe the effect of ischemic preconditioning on cyclinD1 expression in rat liver cells during early ischemic reperfusion. METHODS: Fifty-four SD rats were randomly divided into ischemic preconditioning group (IP), ischemia/ reperfusion group (IR) and sham operation group (SO). The IP and IR groups were further divided into four sub-groups (n - 6). Sham operation group (SO) served as the control group (n = 6). A model of partial liver ischemia/reperfusion was used, in which rats were subjected to liver ischemia for 60 min prior to reperfusion. The animals in the IP group underwent ischemic preconditioning twice for 5 min each time prior to the ischemia/reperfusion challenge. After 0, 1, 2, and 4 h of reperfusion, serum and liver tissue in each group were collected to detect the level of serum ALT, liver histopathology and expression of cyclinDi mRNA and protein. Flow cytometry was used to detect cell cycle as the quantity indicator of cell regeneration. RESULTS: Compared with IR group, IP group showed a significantly lower ALT level in 1 h to 4 h sub-groups (P < 0.05). Proliferation index(PI) indicated by the S-phase and G2/M-phase ratio [(S G2/M)/(G0/G1 S G2/M)] was significantly increased in IP group at 0 and 1 h (26.44±7.60% vs 18.56±6.40%,41.87±7.27% vs 20.25±6.70%, P < 0.05). Meanwhile, cyclinDi protein expression could be detected in IP group. But in IR group, cyclinDi protein expression occurred 2 h after reperfusion. The expression of cyclinDi mRNA increased significantly in IP group at 0 and 1 h (0.568±0.112 vs 0.274±0.069, 0.762±0.164 vs 0.348±0.093, P < 0.05). CONCLUSION: Ischemic preconditioning can protect liver cells against ischemia/reperfusion injury, which may be related to cell proliferation and expression of cyclinD1 during early ischemic reperfusion.     

过氧亚硝基阴离子在哮喘豚鼠气道高反应性中的作用

目的 探讨哮喘豚鼠内过氧亚硝基阴离子（ＯＮＮＯＯ＾－）的生成及其在哮喘气道高反应性形成中的作用。方法 １８只哮喘豚鼠模型随机分为３组：（１）哮喘组（６只）：用１０％卵蛋白１ｍｌ腹腔注射液致敏,２周后用１％卵蛋白超声雾化吸入复制豚鼠哮喘模型。（２）哮喘加氨基胍（ＡＧ）组（６只）：该喘同哮喘组,在每次诱喘前１ｈ腹腔注射ＡＧ１０ｍｇ／ｋｇ。（３）正常对照组（６只）：用生理盐水代替诱喘剂。每组哮喘豚鼠均用     

Protein nitration, metabolites of reactive nitrogen species, and inflammation in lung allografts

This study investigated nitration and chlorination of epithelial lining fluid (ELF) proteins in patients (n = 29) who had undergone lung allotransplantation. We assayed lung lavage nitrotyrosine (NT) and chlorotyrosine (CT) by HPLC. We measured NT, nitrate (NO(3)(-)), and nitrate (NO(2)(-)) in bronchoalveolar lavage fluid (BALF) and total nitrite (NO(2)(-) + NO(3)(-)) in serum of another group of lung transplant patients (n = 82). In the first group (n = 29), percent nitration of tyrosines (Tyr) (NT/total Tyr x 100) in BALF proteins was: patients, 0.01 (0.00-0.12)%; median (25th-75th% confidence interval), and control subjects 0.01 (0.00-0.02)%. CT (CT/ total Tyr x 100) occurred only in the patients' BALF: 0.01 (0. 00- 0.02)%. In the second group (n = 82), nitrotyrosine (NT) was detected by ELISA in the BALF of patients: 9 (0-41) pmol/mg pro and control subjects: 28 (26-33). Total nitrite (NO(2)(-) + NO(3)(-)) in BALF of the patients: 3.3 (1.9-5.1) microM significantly exceeded that in control subjects: 1.3 (0.8-1.3) microM; p = 0.0133. Serum nitrite also was significantly higher in patients: 37 (26-55) microM than control subjects: 19 (17-20) microM; p = 0.0037. Airway inflammation in transbronchial biopsies (B score) correlated with NT in BALF (p = 0.0369). Lung transplants have increased airway concentrations of reactive nitrogen species (RNS) metabolites. NT, a marker of peroxynitrite (ONOO(-)), is related to the degree of airway inflammation in lung transplants.     

Ginkgo biloba extract （EGb 761） attenuates lung injury induced by intestinal ischemia/reperfusion in rats： Roles of oxidative stress and nitric oxide

AIM： To investigate the effect of ginkgo biloba extract （EGb 761） on lung injury induced by intestinal ischemia/ reperfusion （ Ⅱ/R）. METHODS： The rat model of Ⅱ/R injury was produced by damping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The rats were randomly allocated into sham, Ⅱ/R, and EGb ＋Ⅱ/R groups. In EGb ＋Ⅱ/R group, EGb 761 （100 mg/kg per day） was given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761. Lung injury was assessed by light microscopy, wet-todry lung weight ratio （W/D） and pulmonary permeability index （PPT）. The levels of malondialdehyde （MDA） and nitrite/nitrate （NO2/NO3）, as well as the activities of superoxide dismutase （SOD） and myeloperoxidase （MPO） were examined. Western blot was used to determine the expression of inducible nitric oxide synthase （iNOS）. RESULTS： EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPT （P 〈 0.05 or 0.01）.Moreover, EGb 761 markedly increased SOD activity, reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression （P 〈 0.05 or 0.01）. CONCLUSION： The results indicate that EGb 761 has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOS- induced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.     

Ameliorative effects of sodium ferulate on experimental colitis and their mechanisms in rats

AIM: To investigate the ameliorative effects of sodium ferulate (SF) on acetic acid-induced colitis and their mechanisms in rats.METHODS: The colitis model of Sprague-Dawley rats was induced by intracolon enema with 8 % (WV) of acetic acid.The experimental animals were randomly divided into model control, 5-aminosalicylic acid therapy group and three dose of SF therapy groups. The 5 groups were treated intracolonically and daily (8:00 am) for 7 days 24 h following the induction of colitis. A normal control group of rats clystered with normal saline instead of acetic acid was also included in the study.Pathological changes of the colonic mucosa were evaluated by the colon mucosa damage index (CMDI) and the histopathological score (HS). The insulted colonic mucosa was sampled for a variety of determinations at the end of experiment when the animals were sacrificed by decapitation.Colonic activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), and levels of malondialdehyde (MDA)and nitric oxide (NO) were assayed with ultraviolet spectrophotometry. Colonic contents of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2)were determined by radioimmunoassay. The expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry.RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with acetic acid, which manifested as the significant increase of CMDI, HS, MPO activities, MDA and NO levels,PGE2 and TXB2 contents, as well as the expressions of iNOS,COX-2 and NF-κB p65 proteins in the colonic mucosa,although the colonic SOD activity was significantly decreased compared with the normal control (CMDI: 2.9±0.6 vs0.0±0.0;HS: 4.3±0.9 vs0.7±1.1; MPO: 98.1±26.9 vs24.8±11.5; MDA:57.53±12.36 vs9.21±3.85; NO: 0.331±0.092 vs0.176±0.045;PGE2: 186.2±96.2 vs 42.8±32.8; TXB2: 34.26±13.51 vs 8.83±3.75; iNOS: 0.365±0.026 vs0.053±0.015; COX-2:0.296±0.028 vs0.034±0.013; NF-κB p65:0.314±0.026 vs 0.039±0.012; SOD: 28.33±1.17 vs36.14±1.91; P<0.01).However, these parameters were found to be significantly ameliorated in rats treated locally with SF at the given dose (CMDI: 1.8±0.8, 1.6±0.9; HS: 3.3±0.9, 3.1±1.0; MPO:63.8±30.5, 36.2±14.2; MDA: 41.84±10.62, 37.34±8.58; NO:0.247±0.042; 0.216±0.033; PGE2: 77.2±26.9, 58.4±23.9;TXB2:18.07±14.83; 15.52±8.62; iNOS:0.175±0.018, 0.106±0.019;COX-2: 0.064±0.018, 0.056±0.014; NF-κBp65: 0.215±0.019,0.189±0.016; SOD: 32.15±4.26, 33.24±3.69; P<0.05-0.01).amelioration of colonic mucosal injury as evaluated by CMDI and HS.CONCLUSION: Administration of SF intracolonically may have significant therapeutic effects on the rat model of colitis induced by acetic acid enema, which was probably due to the mechanism of antioxidation, inhibition of arachidonic acid metabolism and NF-κB expression.     

S-nitroso human serum albumin reduces ischaemia/reperfusion injury in the pig heart after unprotected warm ischaemia

AIMS: Uncoupled endothelial nitric oxide synthase (eNOS) is a major contributor to vascular reactive oxygen species generation in ischaemia/reperfusion (I/R) injury. Supplementation of NO by the novel NO donor S-nitroso human serum albumin (S-NO-HSA) may inhibit uncoupling of eNOS (feedback inhibition). METHODS AND RESULTS: Pigs (n = 14; 33.1 +/- 1.7 kg) were continuously monitored for heart rate (HR), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), and coronary flow (CF). Infusion of either human serum albumin (n = 8; controls) or S-NO-HSA (n = 6) lasted 60 min (0.1 micromol/kg/h) starting 15 min prior to ischaemia. After clamping the aorta under cardiopulmonary bypass (CPB), the hearts underwent 15 min of warm, unprotected ischaemia (37 degrees C). Reperfusion lasted 150 min (30 min under CPB; 15 min weaning; additional 105 min reperfusion). In biopsies from non-ischaemic hearts and myocardial biopsies taken after 150 min of reperfusion, high-energy phosphates were measured and the calcium ionophore-stimulated release of NO, superoxide, and peroxynitrite (ONOO(-)) were monitored with nanosensors. Compared with non-ischaemic hearts, the NO level decreased from 930 +/- 25 to 600 +/- 15 nmol/L (P < 0.001) while the superoxide level increased from 45 +/- 5 to 110 +/- 10 nmol/L (P < 0.001) after ischaemia. S-NO-HSA restored the NO level to 825 +/- 20 nmol/L, shifted favourably the [NO]/[ONOO(-)] balance (a marker of eNOS uncoupling) from 1.36 +/- 0.06 (ischaemia) to 3.59 +/- 0.18, significantly improved CF (65 +/- 10 vs. control, 43 +/- 5 mL/min, P < 0.05), MAP (57 +/- 5 vs. 39 +/- 3 mm Hg, P < 0.01), LVSP (106 +/- 5 vs. 81 +/- 4 mm Hg, P < 0.01) and phosphocreatine (PCr) content (41.5 +/- 7.3 vs. 18.0 +/- 5.6 micromol/g protein; P < 0.01) at 150 min of reperfusion. CONCLUSION: Long-lasting release of NO by S-NO-HSA prevented uncoupling of eNOS and thereby improved systolic and diastolic function, myocardial perfusion, and the energetic reserve of the heart after I/R injury.     

Effect of intestinal lymphatic circulation blockage in two-hit rats

INTRODUCTION Multiple organ dysfunction syndrome (MODS) is a common but poorly understood complication in a variety of critical illnesses[1-3]. In recent years, much attention has been paid to the study of MODS, and encouraging progress has been achieved.…     

Intestinal endotoxemia plays a central role in development of hepatopulmonary syndrome in a cirrhotic rat model induced by multiple pathogenic factors

AIM： To characterize the correlation between severity of hepatopulmonary syndrome （HPS） and degree of hepatic dysfunction, and to explore how intestinal endotoxemia （IETM） affects the development of HPS in cirrhotic rats.
METHODS： Male Wister rats were fed with a diet containing maize flour, lard, cholesterol, and alcohol and injected subcutaneously with CCl4 oil solution every two days for 8 wk to induce typical cirrhosis and development of HPS. The animals were also given a nitric oxide （NO） production inhibitor, N^ω-nitro-L-arginine methyl ester （L-NAME） intraperitoneally, and an iNOS inhibitor, aminoguanidine hydrochloride （AG） via gavage daily from the end of the 4th wk to the end of the 6th or 8th wk, or a HO-1 inhibitor, zinc protoporphyrin （ZnPP） intraperitoneally 12 h prior to killing. Blood, liver and lung tissues were sampled.
RESULTS： Histological deterioration of the lung paralleled to that of the liver in the cirrhotic rats. The number of pulmonary capillaries was progressively increased from 6.1 ± 1.1 （count/filed） at the 4th wk to 14.5 ± 2.4 （count/filed） at the 8th wk in the cirrhotic rats. Increased pulmonary capillaries were associated with increased blood levels of lipopolysaccharide （LPS） （0.31 ± 0.08 EU/mL vs control 0.09 ± 0.03 EU/mL）, alanine transferase （ALT, 219.1 ± 17.4 U/L vs control 5.9 ± 2.2 U/L） and portal vein pressure. Compared with normal control animals, the number of total cells in bronchoalveolar lavage fluid （BALF） of the cirrhotic rats at the 8th wk was not changed, but the number of macrophages and the ratio of macrophages to total cells were increased by nearly 2-fold, protein expression of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） started to increase significantly at the 4th wk, and reached its peak at the 8th wk in the lung of cirrhotic rats. The increase of iNOS expression appeared to be quicker than that of eNOS. NO2^-/NO3^- was also increased, which was cor