BACKGROUND: The pringle maneuver (PM), hepatic inflow occlusion, during hepatic surgery reduces intraoperative bleeding and blood transfusion requirement, but hepatic ischemia/reperfusion injury is inevitable. During ischemia, xanthine oxidoreductase is converted to xanthine oxidase (XO), which can serve as a critical source of reactive oxygen species (reduces O2 to O2 .-) that contribute to inflammatory signaling, ischemia-reperfusion injury, and an impaired vascular function. The purpose of the present study was to follow changes of XO activity and O2 .- production during hepatic surgery under PM. METHODS: Eleven patients that underwent hepatectomy under intermittent PM were studied. Blood was withdrawn before PM, and 10 and 20 minutes after final reperfusion. Plasma XO activity was measured using a spectrophotometer after incubating plasma with/without xanthine for one-hour. Superoxide (O2 -) production was followed by measuring by cytochrome c reduction by plasma XO. RESULTS: After final reperfusion, plasma XO activity had increased four-fold (0.36 +/- 0.06 to 1.25 +/- 0.25 mU/ml) with a concomitant increase in O2 .- production (0.66 +/- 0.29 to 1.66 +/- 0.40microM/min). CONCLUSIONS: Significantly more XO is released into the systemic circulation after intermittent PM, with subsequently increased O2 .- production. The significant contribution of XO to hepatic surgery under PM might be beneficially managed using an anesthetic with a known antioxidative effect.
Blood Transfusion ; Cytochromes c ; Hemorrhage ; Hepatectomy ; Humans ; Ischemia ; Plasma* ; Reactive Oxygen Species ; Reperfusion ; Reperfusion Injury ; Superoxides ; Xanthine Dehydrogenase ; Xanthine Oxidase* ; Xanthine*

PURPOSE: In the passive Heymann nephritis (PHN) rat model of membranous nephropathy, complement induces glomerular epithelial cell injury and proteinuria, which is partially mediated by reactive oxygen species (ROS), TGF-beta, and COX-2. In the current study, we determined the effect of a selective COX-2 inhibitor (celecoxib) and vitamin C on the enzyme system associated with ROS, TGF-beta, and COX-2 in PHN. METHODS: Four groups of rats with PHN were dosed with polyethylene glycol vehicle (P; n=4), celecoxib (COXi; n=8), vitamin C (VC; n=8), or celecoxib and vitamin C (COXi+VC; n=8) from days 7-21. Each group was then divided into 2 subgroups reflecting the day of the experiment (day-14 and -21 subgroups). RESULTS: The urine protein was significantly reduced in the VC and COXi+VC groups (subgroup day- 14) compared to the P group (p<0.05). The glomerular TGF-beta expression was reduced in the COXi+ VC group (subgroup day-21) compared to the P group (p<0.05). Glomerular COX-2 expression was increased in the COXi, VC, and COXi+VC groups compared to the P group (p<0.05). The COXi, VC, and COXi+VC groups (subgroup day-21) had decreased activity of lipid peroxide and xanthine oxidase and increased activity of xanthine dehydrogenase, superoxide dismutase, GSH-Px, and catalase. This antioxidant activity was highest in the COXi+VC group (p<0.05). CONCLUSION: Selective COX-2 inhibitors possess antioxidant effects. The combination of a COX-2 inhibitor and vitamin C was more effective than COX-2 inhibitor or vitamin C alone in increasing antioxidant activity and decreasing TGF-beta.
Animals ; Antioxidants ; Ascorbic Acid ; Catalase ; Complement System Proteins ; Cyclooxygenase 2 ; Cyclooxygenase 2 Inhibitors ; Epithelial Cells ; Glomerulonephritis, Membranous ; Polyethylene Glycols ; Proteinuria ; Pyrazoles ; Rats ; Reactive Oxygen Species ; Sulfonamides ; Superoxide Dismutase ; Transforming Growth Factor beta ; Vitamins ; Xanthine Dehydrogenase ; Xanthine Oxidase

Ischemia-reperfusion injury is related with oxygen free radicals; a reason which has been suggested for this is the conversion of xanthine dehydrogenase (XDH) into xanthine oxidase (XO). In the present study, metabolic control of the enzymic conversion by modulating the cellular redox potential was attempted. An amino acid, aspartate, was tested as a possible candidate on the assumption that as a participant in the malate/aspartate shuttle, it might modify the cellular NADH/NAD+ balance. Its effect was studied by measuring the level of lipid peroxidation as a thiobarbituric acid-reactive substance (TEARS) and the conversion ratio of XDH to XO in the perfused-rat livers. The experimental animals, male Sprague Dawley rats were divided into three groups: control, ischemia and ischemia/reoxygenation. To each group, aspartate was infused at 2 mM level. ischemia alone did not affect the level of TEARS or the conversion ratio of the enzyme, regardless of aspartate infusion. In contrast, reoxygenation of previously ischemia liver significantly elevated the level of TEARS and decreased the ratio of XDH to XO; both this level and this ratio were ameliorated by aspartate. The protective role of aspartate against oxidative stress induced by ischemia/reoxygenation can be explained by the fact that aspartate may correct the increased NADH/NAD ratio by facilitating NAD regeneration from NADH through the coupled aspartate aminotransferase/malate dehydrogenase reaction and the malate-aspartate shuttle. Aspartate application may thus contribute to the development of a preventive strategy against ischemia/reperfusion-induced oxidative damages.
Animals ; Aspartic Acid* ; Free Radicals ; Humans ; Ischemia ; Lipid Peroxidation ; Liver* ; Male ; NAD ; Oxidation-Reduction ; Oxidative Stress* ; Oxidoreductases ; Oxygen ; Rats* ; Rats, Sprague-Dawley ; Regeneration ; Reperfusion Injury ; Xanthine Dehydrogenase ; Xanthine Oxidase

Preconditioning of a heart with small doses of catecholamines induces a tolerance against the subsequent lethal ischemia. The present study was performed to find a specific receptor pathway involved with the catecholamine preconditioning and to test if adenosine plays a role in this cardioprotective effect. Isolated rat hearts, pretreated with small doses of alpha- or beta-adrenergic agonists/antagonists, were subjected to 20 minutes ischemia and 20 minutes reperfusion by Langendorff perfusion method. Cardiac mechanical functions, lactate dehydrogenase and adenosine release from the hearts were measured before and after the drug treatments and ischemia. In another series of experiments, adenosine A1 or A2 receptor blockers were treated prior to administration of adrenergic agonists. Pretreatments of a beta-agonist, isoproterenol(10-9 ~ 10-7 M) markedly improved the post-ischemic mechanical function and reduced the lactate dehydrogenase release. Similar cardioprotective effect was observed with an alpha-agonist, phenylephrine pretreatment, but much higher concentration(10-4 M) was needed to achieve the same degree of cardioprotection. The cardioprotective effects of isoproterenol and phenylephrine pretreatments were blocked by a beta1-adrenergic receptor antagonist, atenolol, but not by an alpha1-antagonist, prazosin. Adenosine release from the heart was increased by isoproterenol, and the increase was also blocked by atenolol, but not by prazosin. A selective A1-adenosine receptor antagonist, 1,3-dipropyl-8-cyclopentyl xanthine (DPCPX) blocked the cardioprotection by isoproterenol pretreatment. These results suggest that catecholamine pretreatment protects rat myocardium against ischemia and reperfusion injury by mediation of beta1-adrenergic receptor pathway, and that adenosine is involved in this cardioprotective effect.
Adenosine* ; Adrenergic Agonists ; Animals ; Atenolol ; Catecholamines ; Heart* ; Ischemia ; Isoproterenol ; L-Lactate Dehydrogenase ; Myocardium ; Negotiating ; Perfusion ; Phenylephrine ; Prazosin ; Rats* ; Reperfusion ; Reperfusion Injury ; Xanthine

OBJECTIVETo investigate the changes of xanthine oxidase (XOD), myeloperoxidase (MPO) and mitochondrial succinate dehydrogenase (SDH) in the testis and the protective effect of ganoderma lucidum spores on the testicular tissue of rats with non-insu- lin-dependent diabetes mellitus (NIDDM).

METHODSFifty male Wistar rats were divided randomly into a model, a ganoderma and a normal control group, the first two groups injected with 2% STZ (25 mg/kg) through the peritoneum, and the last one with half-and-half sodium citrate/citrate buffer solution. Two weeks after normal diet, glucose tolerance tests were performed and the rats with abnormal glucose tolerance in the model and ganoderma groups received high-fat and high-carbohydrate food, the latter given ganoderma lycium spores (250 mg/kg x d) in addition, both for 10 weeks and all rats fed alone. Glucose tolerance tests were repeated 1 day before the end of the experiment and the testes of the rats were harvested for the determination of XOD, MPO and SDH.

RESULTSSDH was significantly lower (P < 0.05) while XOD and MPO significantly higher in the model group than in the ganoderma and control groups (P < 0.05). The model rats exhibited abnormal convoluted seminiferous tubules, indistinct parietal layers, decreased or abolished gonepoiesis, luminal peripheral fibrous tissue (interstitial substance) accrementition, basal lamina thickening, and vessel wall fibrous tissue accrementition and sclerosis.

CONCLUSIONGanoderma lucidum spores can protect the testis of diabetic rats by reducing free radical-induced damage to the testicular tissue and enhancing the activity of SDH.

Animals ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Male ; Peroxidase ; metabolism ; Rats ; Rats, Wistar ; Reishi ; Spores, Fungal ; Succinate Dehydrogenase ; metabolism ; Testis ; metabolism ; Xanthine Oxidase ; metabolism

PURPOSE: This study investigated the effect of reducing cisplatin induced nephrotoxicity with DWP-04 that is the compound of Schizandrin C derivative biphenyldimethyl dicarboxylate (DDB), glutathione and selenium. For the purpose of observation is that how DWP-04 has influence on mechanism of reducing cisplatin induced nephrotoxicity with renal function test, free radical formation and detoxification enzyme system in renal tissue. METHODS: Five groups of rats were dosed with vehicle, cisplatin (2 mg/kg i.p.), cisplatin+DWP-04 (100, 200 mg/kg po), or cisplatin+sodium thiosulfate (200 mg/kg i.p.) daily for 4 weeks. RESULTS: Serum creatinine, lactate dehydrogenase and activity of hydroxy radical increased in the cisplatin group and suppressed in the cisplatin+DWP-04 group compared to the cisplatin group. The renal tissue concentration of lipid peroxidase and lipofuscin were increased in the cisplatin group compared to the other groups. The activity of aminopyrine N-demethylase, aniline hydroxylase, aldehyde oxidase and xanthine oxidase, of which free radical formation system in kidney was also decreased in the cisplatin+DWP-04 group compared to the cisplatin and cisplatin+sodium thiosulfate group. The activity of detoxification system of free radical, such as glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were markedly increased in the cisplatin+DWP-04 group than the cisplatin and the cisplatin+sodium thiosulfate group (p<0.05). CONCLUSION: It can be concluded that the mechanism of decreasing cisplatin-induced nephrotoxicity by DWP-04 is that the decreasing of the amount of lipid peroxide and lipofuscin in the renal tissue by increasing activity of the antioxidant defense system and the decreasing of reactive oxygen species by increasing detoxification enzyme activity.
Aldehyde Oxidase ; Aminopyrine N-Demethylase ; Aniline Compounds ; Aniline Hydroxylase ; Animals ; Antioxidants ; Catalase ; Cisplatin ; Creatinine ; Cyclooctanes ; Glutathione ; Glutathione Peroxidase ; Glutathione Transferase ; Kidney ; L-Lactate Dehydrogenase ; Lignans ; Lipofuscin ; Peroxidase ; Polycyclic Compounds ; Rats ; Reactive Oxygen Species ; Renal Insufficiency ; Selenium ; Superoxide Dismutase ; Xanthine Oxidase

The cytotoxic effects of oxygen free radicals and the antioxidative effect of ginseng saponin (SPN) on cardiac endothelial cell cultures derived from 3-day old rats were studied. Reactive oxygen species were generated by hypoxanthine (HX) and xanthine oxidase (XO) mixture to the culture medium. Exposure of cardiac endothelial cells to this oxygen-radical-generating system resulted in significant time-dependent decrease of MTT activity and increase of lactate dehydrogenase (LDH) release. These results correlated well with the morphological examination of randomly selected cultured cardiac endothelial cells, which showed large cytoplasmic vacuoles, disordered organelles, pronounced increase of endoplasmic reticular swelling, and decreased maintenance of membrane integrity. The decrease in cell viability and increase of LDH release induced by the oxygen free radicals in cardiac endothelial cell cultures were blocked during the first two hours by antioxidants such as ginseng saponin (SPN), deferoxamine (DFX), and ginseng saponin/deferoxamine mixture (SPN/DFX). These antioxidative effects were significantly greater in the SPN-treated group than in the other antioxidant-treated groups. Especially, the cells of the SPN-treated group showed well developed cytoskeletons, which enabled them to firmly attach to the culture vessel. In conclusion, these results indicate that ginseng saponin has a significant antioxidative effect on cardiac endothelial cells in culture and plays an important role in stimulating the formation of cytoskeleton and maintaining the integrity of cell membrane.
Animals ; Antioxidants ; Cell Membrane ; Cell Survival ; Cytoplasm ; Cytoskeleton ; Deferoxamine ; Endothelial Cells* ; Free Radicals ; Hypoxanthine ; L-Lactate Dehydrogenase ; Membranes ; Organelles ; Oxygen ; Panax* ; Rats ; Reactive Oxygen Species ; Saponins* ; Vacuoles ; Xanthine Oxidase

OBJECTIVETo observe the antioxidant effects of water extract of Carthamus tinctorius on ox-LDL induced injury in rat cardiac microvascular endothelial cell and detecting oxygen derived free radicals (OFR) to explore the antioxidant mechanisms.

METHODBy using the third generation of rat cardiac microvascular endothelial cells (rCMEC), the protection of water extract of C. tinctorius was investigated after ox-LDL (100 mg x L(-1) induced damage. The supernatant was collected for detecting lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), xanthine oxidase (XOD), glutathione peroxidase (GSH-Px), nitric oxide (NO), nitric oxide synthase (NOS) activity, and cell suspension was collected for detecting reactive oxygen species (ROS) by electron spin resonance (ESR).

RESULTWater extract of C. tinctorius increased the rCMEC survival rate, reduced LDH, MDA and XOD levels, and improved SOD, GSH-Px and NOS activity, while in the cell suspension ROS signal decreased significantly.

CONCLUSIONWater extract of C. tinctorius has antioxidation. The mechanisms are likely related with scavenging of free radicals, enhancing its clearance, enhancing endogenous antioxidant activity.

Animals ; Carthamus tinctorius ; chemistry ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Electron Spin Resonance Spectroscopy ; methods ; Endothelial Cells ; drug effects ; metabolism ; Enzyme Activation ; drug effects ; Glutathione Peroxidase ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lipoproteins, LDL ; pharmacology ; Microvessels ; cytology ; Nitric Oxide Synthase ; metabolism ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Water ; chemistry ; Xanthine Oxidase ; metabolism

This paper is aimed to study the metabolic kinetics of nicousamide in rat liver microsomes and cytosol and to identify the major metabolite and drug metabolizing enzymes involved in the metabolism of nicousamide in rat and human liver microsomes by selective inhibitors in vitro. The concentration of nicousamide was determined by HPLC-UV method. The metabolite of nicousamide in rat and human liver microsomes was isolated and identified by LC-MS/MS. The major metabolite of nicousamide in rat and human liver microsomes was identified to be 3-(3'-carboxy-4'-hydroxy-anilino-carbo-)-6-amino-7-hydroxy-8-methyl-coumarin (M1). The metabolite of nicousamide in rat plasma, urine, bile and liver was consistent with M1. The metabolism of nicousamide can be catalyzed by several reductases, including CYP450 reductases, cytochrome b5 reductases and CYP2C6 in rat liver microsomes, as well as xanthine oxidase and DT-diaphorase in rat liver cytosol.
Adenosine Monophosphate ; pharmacology ; Allopurinol ; pharmacology ; Aniline Compounds ; metabolism ; Animals ; Cimetidine ; pharmacology ; Coumarins ; metabolism ; Cytochrome P-450 Enzyme Inhibitors ; Cytochrome P450 Family 2 ; Cytochrome-B(5) Reductase ; antagonists & inhibitors ; Cytosol ; metabolism ; Dicumarol ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Female ; Humans ; Liver ; cytology ; metabolism ; Male ; Microsomes, Liver ; metabolism ; Mitochondria, Liver ; metabolism ; NAD(P)H Dehydrogenase (Quinone) ; antagonists & inhibitors ; Propylthiouracil ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Steroid 21-Hydroxylase ; antagonists & inhibitors ; Xanthine Oxidase ; antagonists & inhibitors