Ischemic and reperfusion injury of cyanotic myocardium in chronic hypoxic rat model: changes in cyanotic myocardial antioxidant system

OBJECTIVE: The objective was to evaluate the effect of left ventricular function on cyanotic myocardium after ischemia-reperfusion and to determine the effect of cyanosis on the myocardial antioxidant system. METHODS: Cyanotic hearts (cyanotic group) were obtained from rats housed in a hypoxic chamber (10% oxygen) for 2 weeks and control hearts (control group) from rats maintained in ambient air. Isolated, crystalloid perfused working hearts were subjected to 15 minutes of global normothermic ischemia and 20 minutes of reperfusion, and functional recovery was evaluated in the two groups. Myocardial superoxide dismutase, glutathione peroxidase, glutathione reductase activity, and reduced glutathione content were measured separately in the cytoplasm and mitochondria at the end of the preischemic, ischemic, and reperfusion periods. RESULTS: Mean cardiac output/left ventricular weight was not significantly different between the two groups. Percent recovery of cardiac output was significantly lower in the cyanotic group than in the control group (56.1% +/- 5.7% vs 73.0% +/- 3.1%, p = 0.001). Mitochondrial superoxide dismutase, mitochondrial and cytosolic glutathione reductase activity, and cytosolic reduced glutathione were significantly lower in the cyanotic group than in the control group at end-ischemia (superoxide dismutase, 3.7 +/- 1.3 vs 5.9 +/- 1.5 units/mg protein, p = 0.012; mitochondrial glutathione reductase, 43.7 +/- 14.0 vs 71.0 +/- 30.3 munits/mg protein, p = 0.039; cytosolic glutathione reductase, 13.7 +/- 2.0 vs 23.2 +/- 4.2 munits/mg protein, p < 0.001; and reduced glutathione, 0.69 +/- 0.10 vs 0.91 +/- 0.24 microgram/mg protein, p = 0.037). CONCLUSIONS: Cyanosis impairs postischemic functional recovery and depresses myocardial antioxidant reserve during ischemia. Reduced antioxidant reserve at end-ischemia may result in impaired postischemic functional recovery of cyanotic myocardium.     

Biological verification of fluid-to-particle interfacial heat transfer coefficients in a pilot scale holding tube simulator

Mesothelioma is a malignant pleural or intraperitoneal tumor attributable to asbestos exposure in more than 80% of the cases. Manganese superoxide dismutase (MnSOD), a mitochondrial superoxide radical scavenging enzyme, is low in most tumors but is known to be induced by asbestos fibers and certain cytokines. Induction of MnSOD may be associated in asbestos-related pulmonary diseases in vivo. We investigated here MnSOD specific activity and MnSOD mRNA level using healthy human lung tissue, SV40-transformed human pleural mesothelial cells (Met5A), and six human malignant mesothelioma cell line cells. Total SOD (CuZnSOD + MnSOD) and MnSOD activities were 20.0 +/- 4.8 U/mg protein and 3.2 +/- 1.2 U/mg protein in healthy human lung tissue, and 25.6 +/- 10.7 U/mg and 3.8 +/- 1.0 U/mg in Met5A cells, respectively. In four mesothelioma cell lines MnSOD activity was significantly elevated, the highest activity (30.1 +/- 8.2 U/mg) was almost 10-fold compared to the activity in Met5A cells. The steady state mRNA level of MnSOD was low in Met5A cells and markedly higher in all mesothelioma cell lines roughly in proportion with enzyme activities. Cytotoxicity experiments, which were conducted in four cell lines, indicated that cells containing high MnSOD mRNA level and activity were resistant to the mitochondrial superoxide-producing agent menadione. In conclusion, our results suggest that human mesothelioma may express high levels of MnSOD, which is associated with high oxidant resistance of these cells.     

Cellular Ca2+ ATPase activity in diabetes mellitus

Basal and maximal Ca2+ ATPase activity was studied in erythrocytes of 29 healthy controls, 15 patients with insulin-dependent diabetes mellitus (IDDM) and 22 patients with non-insulin-dependent diabetes mellitus (NIDDM). Basal and maximal Ca2+ ATPase activity was significantly decreased in insulin-dependent diabetes mellitus (8.4 +/- 0.5 and 22.5 +/- 1.1 pmol/10(6) RBC/min) and non-insulin-dependent diabetes mellitus (7.3 +/- 1.0 and 18.6 +/- 1.8 pmol/10(6) RBC/min) compared to healthy controls (9.3 +/- 1.0 and 24.6 +/- 1.1 pmol/10(6) RBC/min). Maximal Ca2+ ATPase activity showed a significant correlation to systolic blood pressure in both insulin-dependent diabetes mellitus and non-insulin-dependent diabetes mellitus. There was no significant correlation of maximal Ca2+ ATPase activity to fasting serum glucose concentration and to HbA1 levels. Maximal Ca2+ ATPase activity was significantly correlated to creatinine clearance in non-insulin-dependent diabetes mellitus, but not in insulin-dependent diabetes mellitus. It is concluded that a decreased cellular Ca2+ ATPase activity may predispose to the development of hypertension in diabetes mellitus.     

Overexpression of manganese-superoxide dismutase prevents methylmercury toxicity in HeLa cells

HeLa cells were stably transformed with plasmid constructs that allowed constitutive expression of antioxidant enzymes such as catalase, glutathione peroxidase (GSH-Px), Cu,Zn-superoxide dismutase (Cu,Zn-SOD) or Mn-superoxide dismutase (Mn-SOD) to examine the involvement of reactive oxygen generation in methylmercury toxicity. Overexpression of catalase, GSH-Px or Cu,Zn-SOD did not affect the sensitivity of HeLa cells against methylmercury. However, the sensitivity of HeLa cells against methylmercury was decreased by overexpression of Mn-SOD, an enzyme localized in matrix of mitochondria and which decomposes superoxide anions. These results suggest that formation of superoxide anions in the mitochondria might be involved in the mechanism of the cytotoxicity of methylmercury.     

Effect of siderophores, catecholamines, and catechol compounds on Listeria spp. Growth in iron-complexed medium

The objective of our study was to elucidate the involvement of interleukin (IL)-8 in the hCG-induced rabbit ovulatory process. After administering hCG (100 IU i.v.), we examined myeloperoxidase (MPO) activity, which represents neutrophil accumulation; neutrophil elastase (NE) activity, which is an indicator of neutrophil activity; and levels of IL-8 in the ovaries. The maximal level of IL-8 was observed before MPO and NE activities reached a peak: production of IL-8, MPO, and NE activities peaked, respectively, at 4 h (5.58 +/- 0.88 pg/mg ovary, n = 13), 6 h (1.07 +/- 0.13 deltaA/min per gram ovary, n = 8), and 9 h (18.89 +/- 1.05 U/g ovary, n = 8). Anti-rabbit IL-8 antiserum given i.v. significantly reduced the maximal levels of hCG-induced MPO activity (antiserum vs. control; 0.34 +/- 0.04 vs. 1.12 +/- 0.11 deltaA/min per gram ovary, n = 14, p < 0.001) and NE activity (8.14 +/- 0.85 vs. 18.30 +/- 0.79 U/g ovary, n = 14, p < 0.001). The hCG-induced ovulation rate was significantly inhibited by the antiserum (50.5% vs. 83.9%, n = 14, p < 0.001). Intraperitoneal injection of 100 mg/kg of ONO-5046, a specific NE inhibitor, also attenuated the ovulation rate (ONO-5046 vs. vehicle; 56.0% vs. 74.0%, n = 14, p < 0.05). These findings clearly indicate that IL-8 has an important role in the hCG-induced ovulatory process through the accumulation and activation of neutrophils.     

A novel and simple immunocapture assay for determination of gelatinase-B (MMP-9) activities in biological fluids: saliva from patients with Sj?gren's syndrome contain increased latent and active gelatinase-B levels

Here we describe a new principle for accessing the activity of the different members of the human matrix-metalloproteinases (MMPs) by a colorimetric assay. Using protein engineering, a modified pro-urokinase was made in which the activation sequence, normally recognized by plasmin (ProArgPheLys/IleIleGlyGly), was replaced by a sequence that is specifically recognized by MMPs (ArgProLeuGly/IleIleGlyGly). The active urokinase resulting from the activation of this modified pro-urokinase by MMPs can be measured directly using a chromogenic peptide substrate for urokinase. The assay has been made specific for MMP-9 using an MMP-9 specific monoclonal antibody. Using this antibody MMP-9 is captured from biological fluids or tissue culture media, and MMP-activity of both active and latent MMP-9 can be analysed. We determined the gelatinase-B (MMP-9) activity present in saliva from patients with Sj?gren's syndrome. Using a general gelatinase assay with radioactively-labeled gelatinated collagen it was observed that gelatinase activity was slightly, though not significantly, increased in patients: general gelatinase activity in patients versus healthy controls: 17.0 +/- 4.9 vs 12.2 +/- 2.5 x 10(4) cpm/ml (p > 0.05, and 44.0 (4.0 vs 36.1 +/- 1.9 x 10(4) cpm/ml (p > 0.05), for active and latent gelatinase, respectively. However, using the immunocapture activity assay (using modified urokinase) specifically MMP-9 activity was measured, which was significantly increased in saliva from patients compared to healthy controls: MMP-9 (already active): patients 8.9 +/- 2.5 U/mg, controls 1.0 +/- 0.5 U/mg (p = 0.002); latent plus active MMP-9: patients 53.1 +/- 9.8 U/mg, controls 16.5 +/- 2.6 U/mg (p = 0.01). This assay, measuring MMP-9 activity using modified pro-urokinase as a substrate can easily be adapted for the specific detection of the various members of the MMP-family or other difficult to measure proteases, in a format that can be used for high throughput screening of compounds or samples.     

Effect of hygiene measures, water sanitation and oral rehydration therapy on diarrhea in children less than five years old in the south of Ivory Coast

BACKGROUND: Gastric sucrose permeability is a noninvasive marker that reliably increases in association with gastrointestinal injury due to use of nonsteroidal antiinflammatory drugs. Despite the effect of Helicobacter pylori infection on the gastric mucosa, in a previous study we were unable to demonstrate that H. pylori infection was associated with abnormal gastric sucrose permeability. Our goal in this study was to explore further whether H. pylori infection changed gastric permeability; therefore, we evaluated the effect of treatment of H. pylori infection on gastric permeability to sucrose and the relation of sucrose permeability to density of polymorphonuclear leukocytes. MATERIALS AND METHODS: Five hundred milliliters of a solution containing 100 gm of sucrose was ingested by the subject at bedtime. Overnight urine was collected and assayed for sucrose by high-performance liquid chromatography. Sucrose permeability was assessed both before and approximately 4 weeks after anti-H. pylori therapy. RESULTS: Seventeen asymptomatic H. pylori-infected volunteers participated; 8 were cured. Sucrose permeability was in the range commonly found in normal controls both before and after anti-H. pylori therapy (mean excretion, 76.3 mg; range, 13-171 mg). Gastric sucrose permeability correlated with the density of polymorphonulcear cell infiltration of the mucosa. Cure of the H. pylori infection was associated with a small but significant decrease in sucrose permeability (98.8 +/- 18 mg to 51.7 +/- 9.8 mg (p = .01). Sucrose permeability was greater in those with a high density of mucosal polymorphonuclear cells compared to those with lower scores (119.5 +/- 4 vs 71.4 +/- 13 for those with scores > or = 5 compared to scores < or = 4; p = .023). Failed therapy resulted in an increase in the mucosal density of polymorphonuclear infiltration and sucrose permeability (56.4 +/- 13 mg-99.7 +/- 19 mg pretreatment vs posttreatment, respectively; p = .031). CONCLUSION: H. pylori gastritis causes a small but measurable increase in gastric permeability to sucrose that may reflect epithelial transmigration of neutrophils.     

Comparison of three different methods for radiolabelling human activated T lymphocytes

The purpose of this study was to determine both the selenium (Se) level and glutathione peroxidase (GSH-Px) activity in plasma, erythrocytes and platelets from 51 healthy Japanese individuals. The Se levels (mean +/- SD) of plasma, erythrocytes and platelets were 117.4 +/- 15.7 micrograms/L, 0.954 +/- 0.159 microgram/g hemoglobin, and 4.93 +/- 1.52 ng/mg protein, respectively, and GSH-Px activity was 318 +/- 50 U/L, 18.0 +/- 5.0 U/g hemoglobin, and 0.142 +/- 0.035 U/mg protein, respectively. There was a negative correlation between age and the platelet Se level in men (r = -0.761, p < 0.001), and a positive correlation between the plasma and platelet GSH-Px activities in women (r = 0.663, p < 0.001).     

Decreased pancreatic somatostatin (SRIF) concentration in spontaneously diabetic mice

Spontaneously diabetic C57BL/6J obob and C57BL/Ks dbdb mice have been shown to have significantly decreased immunoassayable pancreatic somatostatin concentrations compared to lean littermate controls at 11-12 weeks: obob 1.06+/-0.15 pg/mug protein (n=10) vs control 1.94+/-0.-6 pg/mug protein (n=10) (mean +/- SE; p less than 0.005); dbdb 0.7+/-0.2 pg/mug protein (n=8) vs control 1.5+/-0.2 pg/mug protein (n=8) (mean +/- SE; p less than 0.005). An inverse relationship between circulating insulin levels and pancreatic SRIF concentration is suggested.     

Lecithinized superoxide dismutase attenuates phorbol myristate acetate-induced injury in isolated dog lung

Lecithinized superoxide dismutase, a lecithin derivative bound to recombinant human CuZn superoxide dismutase, has a higher affinity for cells such as polymorphonuclear leukocytes and endothelial cells than recombinant human CuZn superoxide dismutase has. We determined the protective effects of lecithinized superoxide dismutase on the increased microvascular permeability induced by phorbol myristate acetate (PMA) in isolated dog lungs. Microvascular permeability was assessed by the capillary filtration coefficient (Kf,c) and solvent drag reflection coefficient (sigma(f)). PMA (13.3 microg) increased microvascular permeability, as evidenced by an increase in Kf,c and the small sigma(f) value. Lecithinized superoxide dismutase at both low (4800 U) and high doses (48,000 U) inhibited the PMA-induced increase in Kf,c, but only the high dose of lecithinized superoxide dismutase attenuated the decrease in sigma(f). Recombinant human CuZn superoxide dismutase did not affect the PMA-induced increase in vascular permeability at either a low (4800 U) or a high dose (48,000 U). These findings suggest that lecithinized superoxide dismutase has a protective effect against oxygen radical-induced lung injury in isolated dog lungs.     

Overexpression of human superoxide dismutase inhibits oxidation of low-density lipoprotein by endothelial cells

Oxidation of LDL in the subendothelial space has been proposed to play a key role in atherosclerosis. Endothelial cells produce superoxide anions (O2.-) and oxidize LDL in vitro; however, the role of O2.- in endothelial cell-induced LDL oxidation is unclear. Incubation of human LDL (200 microg/mL) with bovine aortic endothelial cells (BAECs) for 18 hours resulted in a 4-fold increase in LDL oxidation compared with cell-free incubation (22.5+/-1.1 versus 6.3+/-0.2 [mean+/-SEM] nmol malondialdehyde/mg LDL protein, respectively; P<0.05). Under similar conditions, incubation of LDL with porcine aortic endothelial cells resulted in a 5-fold increase in LDL oxidation. Inclusion of exogenous copper/zinc superoxide dismutase (Cu/ZnSOD, 100 microg/mL) in the medium reduced BAEC-induced LDL oxidation by 79%. To determine whether the intracellular SOD content can have a similar protective effect, BAECs were infected with adenoviral vectors containing cDNA for human Cu/ZnSOD (AdCu/ZnSOD) or manganese SOD (AdMnSOD). Adenoviral infection increased the content and activity of either Cu/ZnSOD or MnSOD in the cells and reduced cellular O2.- release by two thirds. When cells infected with AdCu/ZnSOD or AdMnSOD were incubated with LDL, formation of malondialdehyde was decreased by 77% and 32%, respectively. Two other indices of LDL oxidation, formation of conjugated dienes and increased LDL electrophoretic mobility, were similarly reduced by SOD transduction. These data suggest that production of O2.- contributes to endothelial cell-induced oxidation of LDL in vitro. Furthermore, adenovirus-mediated transfer of cDNA for human SOD, particularly Cu/ZnSOD, effectively reduces oxidation of LDL by endothelial cells.     

Involvement of oxygen-derived free radicals in L-arginine-induced acute pancreatitis

This study was aimed at an assessment of the role of oxygen-derived free radicals in the pathogenesis of L-arginine (Arg)-induced acute pancreatitis in rat, by measuring the levels of malonyl dialdehyde (MDA), glutathione peroxidase (GPx), catalase, and superoxide dismutase (Mn- and Cu,Zn-SOD) in the pancreatic tissue, and evaluating the protective effect of the xanthine oxidase inhibitor allopurinol. Acute pancreatitis was induced in male Wistar rats by injecting 2 x 250 mg/100 g body weight of Arg intraperitoneally in a 1-hr interval, as a 20% solution in 0.15 M NaCl. Control rats received the same quantity of glycine. Allopurinol, 100 or 200 mg/kg, was administered subcutaneously 30 min before the first Arg injection. Rats were killed at 6, 12, 24, and 48 hr following Arg administration, and acute pancreatitis was confirmed by a serum amylase level elevation and typical inflammatory features observed microscopically. The serum level of amylase reached the peak level at 24 hr after the Arg injection (30,800+/-3813 vs 6382+/-184 units/liter in the control) and normalized at 48 hr. The tissue concentration of MDA was significantly elevated at 24 hr and reached the peak value at 48 hr (5.00+/-1.75 vs 0.28+/-0.05 nM/mg protein in the control). The catalase and Mn-SOD activities were significantly decreased throughout the study, while the GPx activity was significantly reduced at 6 and 12 hr, and the Cu,Zn-SOD activity was significantly lower at 12 hr after the Arg injection as compared with the controls. Allopurinol treatment markedly reduced the serum amylase elevation (12.631+/-2.257 units/liter at 24 hr) and prevented the increase in tissue MDA concentration (0.55+/-0.09 nM/mg protein at 48 hr). Both doses of allopurinol significantly ameliorated the pancreatic edema, necrosis, and inflammation at 48 hr after Arg administration. Oxygen-derived free radicals are generated at an early stage of Arg-induced acute pancreatitis. Prophylactic allopurinol treatment prevents the generation of reactive oxygen metabolites, reduces the serum amylase concentration, and exerts a beneficial effect on the development of histopathological changes.     

Platelet cNOS activity is reduced in patients with IDDM and NIDDM

Several studies in vitro and in vivo suggest that the nitric oxide (NO) production is impaired in diabetes mellitus. Reduced levels of NO could contribute to vascular alteration facilitating platelet-vascular wall interaction, adhesion of monocytes to endothelium, vascular smooth muscle proliferation and by decreasing endothelium-dependent vasodilation. In this study we evaluated the activity of the constitutive nitric oxide synthase (cNOS) in platelets of patients with insulin-dependent diabetes mellitus (IDDM) and with non-insulin-dependent diabetes mellitus (NIDDM). When compared to that of normal subjects, cNOS activity is significantly lower in patients with IDDM and with NIDDM (1.57 +/- 0.25 vs. 0.66 +/- 0.10 fmol/min/10(9) PLTs and 1.57 +/- 0.25 vs. 0.67 +/- 0.08, respectively; p<0.005). These data demonstrate that the platelet cNOS activity is decreased in diabetes mellitus.     

Beneficial effect of raxofelast, an hydrophilic vitamin E analogue, in the rat heart after ischemia and reperfusion injury

Several studies report that among the antioxidant agents used to reduce injury after myocardial ischemia/reperfusion, analogues of vitamin E (VE) seem to have a significant efficacy. Raxofelast is a potent antioxidant agent under investigation, structurally related to VE, having an excellent bioavailability and favourable physicochemical properties. We assessed raxofelast in a rat model of myocardial damage induced by 1 h of left coronary artery occlusion followed by 6 h of reperfusion. Myocardial ischemia/reperfusion produced: wide tissue necrosis (50.3+/-10.3%); membrane peroxidation, evaluated by assessing cardiac malondialdehyde (MAL) (87.8+/-15.8 nmol/g tissuev 9.53+/-2.4 nmol/g tissue) and plasma conjugated dienes (CD) (8.73+/-1.86 DeltaABS/mlv 1.61+/-0.45 DeltaABS/ml); endogenous antioxidant wasting [cardiac VE=23.5+/-10.2 nmol/g tissuev 61.4+/-13.4 nmol/g tissue, cardiac reduced glutatione (GSH)=2.15+/-1.23 micromol/g proteinv 7.34+/-0.92 micromol/g protein and cardiac superoxide dismutase (SOD)=8.9+/-4.1 U/mg proteinv 17. 5+/-4.2 U/mg protein]; depressed mean arterial blood pressure (MAP) (61.4+/-5.8 mmHgv 85.3+/-6.2 mmHg); heart rate (HR) (275+/-35 beats/minv 368+/-34 beats/min) and left-ventricular derivative developed force (LV dP/dtmax) (1050+/-187 mmHg/sv 2520+/-194 mmHg/s); and cardiac neutrophil accumulation, evaluated by assessing cardiac myeloperoxidase (MPO) (9.23+/-2.1 U/g tissuev 0.92+/-0.12 U/g tissue). Administration of raxofelast (25, 50 and 100 mg/kg i.p. 5 min after occlusion) limited myocardial necrosis (22.3+/-14.8%P<0. 005, following the highest dose), reduced lipid peroxidation (MAL=43. 5+/-14.7 nmol/g tissueP<0.001 and CD=4.01+/-2.21 DeltaABS/mlP<0.001, following the highest dose), restored the endogenous antioxidants VE (52.8+/-14.2 nmol/g tissueP<0.001, following the highest dose), SOD (14.2+/-2.7 U/mg proteinP<0.001, following the highest dose) and GSH (4.92+/-1.33 micromol/g proteinP<0.005, following the highest dose), improved hemodynamic parameters (MAP=68.1+/-5.3 mmHgP<0.05, HR=317+/-27 beats/minP<0.05, LV dP/dtmax=1427+/-143 mmHg/sP<0.05, following the highest dose) and reduced myocardial neutrophil infiltration (MPO=5.1+/-1.5 U/g tissueP<0.001, following the highest dose). These data suggest that raxofelast could be considered a useful drug to reduce myocardial infarction.     

Chest physiotherapy and post-extubation atelectasis in infants

The present study describe the role of copper zinc superoxide dismutase (CuZnSOD) in the short-term treatment of experimental colitis induced with 8% acetic acid. The colonic mucosa damage index in the group of 10 rats treated intravenously with 30,000 U/kg CuZnSOD was significantly decreased when compared with the control group (10 rats) treated with normal saline (0.4 +/- 0.6 vs 1.5 +/- 0.5 p < 0.01). Assay of SOD in the control group was 0.3 +/- 0.08 and in the SOD treated group, SOD was significantly increased to 0.8 +/- 0.1, glutathione peroxidase was 44.8 +/- 6.3 in the control and 56.4 +/- 9.1 in the treated group (difference not significant). Both myeloperoxidase activity (14.0 +/- 2.5 vs 22.7 +/- 2.5) and lipid peroxidation products (13.8 +/- 2.9 vs 52.9 +/- 9.6) were significantly lower in the colonic mucosa of the SOD treated group in comparison with the control. These results indicate that the anti-inflammatory effects of CuZnSOD were mainly the removal of oxygen free radicals and indirectly the prevention of lipid peroxidation. This study suggests that CuZnSOD may be beneficial in the treatment of patients with ulcerative colitis. However, our experimental data suggest that this treatment will not have strong effects on the control of severe ulcerative colitis.     

Laparoscopic treatment of genitofemoral neuralgia

Isolated human neutrophils produced no detectable (< 10 nM) nitric oxide (NO) before or after activation with phorbol 12-myristate 13-acetate (PMA) or a chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine. Physiological levels of NO (1 microM) added before or after neutrophil activation had no effect on their respiratory burst oxygen consumption. Neutrophils activated with PMA caused very rapid breakdown of exogenously added NO. NO breakdown rates recorded at 250 nM NO were 0.09 +/- 0.02 and 3.77 +/- 0.23 nmol NO/min/10(6) cells (n = 3) before and after activation respectively and addition of copper-zinc superoxide dismutase during activation significantly decreased this rate (1.06 +/- 0.09 nmol NO/min/10(6) cells (n = 3)), suggesting that superoxide (O2-) production was mainly responsible for the NO breakdown. These results suggest that activation of human neutrophils in vivo will dramatically decrease surrounding NO levels, potentially causing vasoconstriction, platelet aggregation and adhesion and peroxynitrite (ONOO-) formation.     

Inhibitory action of spinorphin, an endogenous regulator of enkephalin-degrading enzymes, on carrageenan-induced polymorphonuclear neutrophil accumulation in mouse air-pouches

Whether spinorphin, an endogenous regulator of enkephalin-degrading enzymes, plays a role in an anti-inflammatory action was examined, using a mouse air-pouch assay as a model of acute inflammation. Repeated intravenous administration (6 times) of spinorphin every hour significantly suppressed carrageenan-induced polymorphonuclear neutrophil (PMN) accumulation, an indicator of inflammation (3.21+/-0.95 x 10[6] cells vs 8.92+/-0.96 x 10[6] cells, 10mg/kg spinorphin-treated vs saline-treated group, n=5, P<0.01) at 6 hr. The combination of spinorphin and leuhistin (2 mg/kg, i.v.), a specific inhibitor of aminopeptidase N (APN), markedly suppressed the PMN accumulation induced by carrageenan (1.11+/-0.17 x 10[6] cells, 88% inhibition compared to the saline-treated group, n=5, P<0.01). This inhibition was less than, but comparable to that of dexamethasone (30 mg/kg/one shot, i. v.), a representative anti-inflammatory drug. These results indicate that spinorphin may be an endogenous anti-inflammatory regulator, its inhibitory activity being modulated by APN.     

Effect of transfection with a superoxide dismutase expression plasmid on xanthine/xanthine oxidase-induced cytotoxicity in cultured rat lung cells

We inserted human Cu, Zn-superoxide dismutase (hSOD) cDNA into the eukaryotic expression plasmid (pRc/CMV) under the control of the cytomegalovirus promoter. The hSOD expression plasmid (pRc/CMV-SOD) was transfected in L2 cells by mean of lipofection. The intracellular SOD activity in pRc/CMV-SOD transfected cells (CMV-SOD cells) was about twice that in host cells. However the level of extracellular SOD activity was similar in CMV-SOD and host cells. When exposed to xanthine (X)/xanthine oxidase (XO) to generate active oxygen species, significantly more CMV-SOD cells than host cells survived. The production of lipid peroxidation in host cells significantly increased in the presence of X/XO, but that in CMV-SOD cells did not change. Thus, transfection with SOD gene effectively prevented X/XO-induced cytotoxicity. The results indicated that increasing the level of intracellular SOD activity protected cells against extracellular superoxide anion stress.     

Attenuation of neutrophil and endothelial activation by intravenous morphine in patients with acute myocardial infarction

To investigate the effects of morphine on neutrophil and endothelial activation, we measured serum levels of intercellular adhesion molecule-1 (ICAM-1), L-selectin, and neutrophil endopeptidase 24.11 (NEP) in 38 patients with acute myocardial infarction (group 1) and 16 control subjects (group 2). In group 1, all the patients underwent blood sampling at initial presentation and 10 minutes later. Twenty of them had 3 mg of morphine administered intravenously immediately after the first sampling (group 1A) and the other 18 after a second sampling (group 1B). The serum levels of ICAM-1 and L-selectin were both significantly higher in groups 1A and 1B than in group 2. In group 1A, the ICAM-1 decreased significantly at second blood samplings (310 +/- 28 vs 368 +/- 30 ng/ml; p <0.001), whereas in group 1B there was no significant change in ICAM-1 (357 +/- 33 vs 359 +/- 26 ng/ml; p = NS). In group 1A, the L-selectin decreased significantly at second blood samplings (2.3 +/- 1.2 mg/L, p <0.001 vs baseline), whereas in group 1B there was no significant change in L-selectin (3.9 +/- 1.0 mg/L, p = NS vs baseline). There was no significant difference in baseline NEP activities between groups 1A and 1B (4.89 +/- 1.22 vs 5.14 +/- 1.57 nmol/mg protein; p = NS). However, the NEP activities at second blood samplings decreased significantly in group 1A (9.88 +/- 1.86 nmol/mg protein, p <0.001 vs baseline), whereas no significant changes were observed in group 1B (5.09 +/- 1.62 nmol/mg protein, p = NS vs baseline). In conclusion, morphine increased NEP activities and thus attenuated shedding of L-selectin and ICAM-1.