Time course and mechanism of oxidative stress and tissue damage in rat liver subjected to in vivo ischemia-reperfusion.

Lats2 is a tumor suppressor and a serine/threonine kinase, acting downstream of mammalian sterile 20 like kinase1 (Mst1), which stimulates apoptosis and inhibits hypertrophy in cardiomyocytes (CM). We investigated the role of Lats2 in mediating myocardial injury after ischemia/reperfusion (IR). Phosphorylation of YAP, an in vivo substrate of Lats2, was increased after 45 minutes ischemia followed by 24 hours reperfusion in control mouse hearts compared with sham, but not in dominant negative (DN) Lats2 transgenic mouse (Tg) hearts, suggesting that Lats2 is activated by IR. The size of myocardial infarction (MI)/area at risk was significantly smaller in Tg mice than in NTg mice (19% and 49%, p<0.01). And there were fewer TUNEL positive cells in Tg than in NTg mice (0.04% and 0.11%, p<0.05). Following 30 min of global ischemia and 60 min of reperfusion in Langendorff perfused heart preparations, left ventricular (LV) systolic pressure (100 vs 71mmHg, p<0.05) and LV developed pressure (79 vs 47 mmHg, p<0.05) were significantly greater in Tg than in NTg mice, indicating that suppression of Lats2 induces better functional recovery after IR. Oxidative stress, as evaluated by 8-OHdG staining, was attenuated in Tg mice. In cultured CMs, DN-Lats2 significantly decreased H 2 O 2 -induced cell death. Overexpression of Lats2 significantly downregulated (51% and 75%, p<0.05), whereas that of DN-Last2 upregulated (100 and 70%, p<0.05), MnSOD and catalase, suggesting that Lats2 negatively regulates expression of antioxidants. Reporter gene assays showed that overexpression of Lats2 significantly inhibits (−70%), whereas knocking down Lats2 by sh-Lats2 increases (+60%), FoxO3-mediated transcriptional activity. Overexpression of Lats2 in CMs inhibited FoxO3 expression, whereas that of DN-Lats2 significantly inhibited FoxO3 downregulation after IR in vivo, suggesting that Lats2 negatively regulates FoxO3 protein expression, which may lead to the downregulation of MnSOD and catalase. Taken together, these results suggest that endogenous Lats2 plays an important role in mediating myocardial injury in response to IR, In part through downregulation of FoxO3 and consequent downregulation of antioxidants and increased oxidative stress in the heart.

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Mechanisms of conversion of xanthine dehydrogenase to xanthine oxidase in ischemic rat liver and kidney

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1988.254.5.g753 ◽

1988 ◽

Vol 254 (5) ◽

pp. G753-G760 ◽

Cited By ~ 11

Author(s):

T. G. McKelvey ◽

M. E. Hollwarth ◽

D. N. Granger ◽

T. D. Engerson ◽

U. Landler ◽

...

Keyword(s):

Xanthine Oxidase ◽

Rat Liver ◽

Ischemia Reperfusion ◽

Xanthine Dehydrogenase ◽

Serum Glutamic Oxaloacetic Transaminase ◽

Liver Model ◽

Damage Process ◽

Liver And Kidney ◽

Sulfhydryl Modification

Previous studies have proposed and supported a role for the proteolytic, irreversible conversion of xanthine dehydrogenase to xanthine oxidase (XO) in postischemic injury in a wide variety of organs. A second mechanism of conversion, due to sulfhydryl modification and reversible with dithiothreitol (DTT), is potentially important but has not been well investigated. In this study rat liver and kidney were found to produce significant amounts of DTT-reversible XO during normothermic global ischemia. Formation of reversible XO precedes that of irreversible XO by approximately 0.5 h with a strong correlation (r = 0.92) existing between the rate of irreversible XO formation and the concentration of reversible XO. The formation of reversible XO is preceded by a depletion of glutathione with concentrations of glutathione during ischemia correlating (r = 0.85) with the observed concentration of reversible XO. While a large increase in the extent of liver damage occurs concurrently with conversion in an in vivo liver model of liver ischemia, an ischemia-reperfusion regimen (1 h of ischemia plus 0.5 h of reperfusion) that resulted in no conversion caused significant elevations in serum glutamic pyruvic transaminase and serum glutamic-oxaloacetic transaminase. Rats depleted of XO by tungsten dieting release 65% less enzyme after the same insult, suggesting that endogenous XO may also participate in the damage process independent of any conversion.

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Galangin Alleviates Liver Ischemia-Reperfusion Injury in a Rat Model by Mediating the PI3K/AKT Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000495553 ◽

2018 ◽

Vol 51 (3) ◽

pp. 1354-1363 ◽

Cited By ~ 7

Author(s):

Yang Li ◽

Liquan Tong ◽

Jingyan Zhang ◽

Yafeng Zhang ◽

Feng Zhang

Keyword(s):

Oxidative Stress ◽

Ischemia Reperfusion Injury ◽

Hepatic Duct ◽

Ischemia Reperfusion ◽

Trauma Surgery ◽

Liver Ischemia ◽

Western Blots ◽

Phosphorylated Akt ◽

Related Proteins

Background/Aims: Liver ischemia-reperfusion (I/R) injury is a pathological process that often occurs during liver and trauma surgery. There are numerous causes of liver I/R injury, but the mechanism is unknown. Galangin (GA) is a flavonoid, a polyphenolic compound widely distributed in medicinal herbs that has anti-inflammatory, antioxidant, and antitumor activity. This study evaluated the protective effect of GA on hepatic I/R injury. Methods: An I/R model was created in male Wistar rats by clamping the hepatoportal vein, hepatic artery and hepatic duct for 30 min followed by reperfusion for 2 h. A hypoxia/restoration (H/R) model was established in buffalo rat liver (BRL) cells by hypoxia for 4 h followed by normoxic conditions for 10 h. The extent of liver injury was assayed by serum ALT/AST, hepatic histology, and MPO activity. Oxidative stress was assayed by serum superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA). Expression of apoptosis-related proteins in BRL cells was assayed in western blots. Expression of AKT and p-AKT proteins in vivo and vitro were assayed in western blots. Results: GA significantly decreased ALT/AST expression, reversed changes in oxidative stress markers induced by I/R, and mediated caspase-3 activity expression of apoptosis-related proteins in vivo and in vitro. Methylthiazol tetrazolium (MTT) assay, flow cytometry, and Hoechst 33258 staining confirmed that GA inhibited apoptosis of BRL cells. GA also increased the expression of phosphorylated AKT after H/R. Conclusion: GA reduced liver I/R injury both in vivo and vitro and inhibited BRL cell apoptosis. PI3K/AKT signaling have been involved. GA may protect against liver I/R and be a potential therapeutic candidate.

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The availability of inorganic sulphate in blood for sulphate conjugation of drugs in rat liver in vivo. (35S)Sulphate incorporation into harmol sulphate

Biochemical Journal ◽

10.1042/bj1720247 ◽

1978 ◽

Vol 172 (2) ◽

pp. 247-251 ◽

Cited By ~ 46

Author(s):

G J Mulder ◽

E Scholtens

Keyword(s):

Plasma Concentration ◽

Rat Liver ◽

Biliary Excretion ◽

Time Course ◽

Specific Radioactivity ◽

Pool Size ◽

Inorganic Sulphate ◽

Initial Decrease ◽

Sulphate Conjugate

1. When Na235SO4 is injected intravenously in rats, it is immediately available for sulphate conjugation of the phenolic drug harmol (7-hydroxyl-1-methyl-9H-pyrido[3,4-b]indole) in the liver. This was established by following the time course of the biliary excretion of the sulphate conjugate of harmol, and the incorporation of [35S]sulphate into harmol sulphate. 2. During the 10min immediately after injection of Na235SO4 re-distribution of [35S]sulphate took place, which resulted in a rapid initial decrease in the plasma concentration of [35S]sulphate; a concomitant decrease in the amount of [35S]sulphate incorporated into harmol sulphate was observed, indicating that the co-substrate of sulphation, adenosine 3′-phosphate 5′-sulphatophosphate, equilibrates rapidly with [35S]sulphate in plasma. 3. The results suggest that the pool size of adenosine 3′-phosphate 5′-sulphatophosphate is very small; therefore the specific radioactivity of [35S]sulphate in plasma determines the specific radioactivity incorporated into sulphate esters at any time.

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In vivo and In vitro Antioxidant Activities of Aqueous and Ethanol Stem Bark Extracts of Vitex doniana on Doxorubicin-induced Oxidative Stress in Rats

Asian Journal of Research in Biochemistry ◽

10.9734/ajrb/2021/v8i230178 ◽

2021 ◽

pp. 44-55

Author(s):

Mohammed Aliyu Sulaiman ◽

Daniel Dahiru ◽

Mohammed Auwal Ibrahim ◽

Ahmed Ibrahim Hayatu

Keyword(s):

Oxidative Stress ◽

Antioxidant Activities ◽

Ischemia Reperfusion ◽

Oral Treatment ◽

Stem Bark ◽

Albino Rats ◽

Associated Diseases ◽

Vitex Doniana

Background: Oxidative stress is involved in the pathogenesis of hypertension, myocardial ischemia-reperfusion injury, atherosclerosis, muscular dystrophy, aging and other associated diseases. Vitex doniana is used in Adamawa, northern Nigeria to treat oxidative stress associated diseases. However, the antioxidative effects of the plant have not been scientifically examined in oxidative stress experimental animal models. The aim of this study is to investigate the in vitro and in vivo antioxidant activities of aqueous and ethanol stem bark extracts of Vitex doniana in oxidative stress model of rats. Methods: The study used 35 adult albino rats weighing 175 ± 25 g, of which 30 were induced with oxidative stress by intraperitoneal injection of doxorubicin (10 mg/kg) for three consecutive days. Animals were treated by oral administration of silymarin (100 mg/kg) and Vitex doniana aqueous or ethanol extract (100 mg/kg and 200 mg/kg) for 14 consecutive days before they were sacrificed on the 15th day and blood was analyzed for biochemical indices of oxidative stress. Results: The results of the phytochemistry showed the presence of alkaloids, tannins, flavonoids, steroids, phenols, saponins, terpenoids, glycosides: and total flavonoids (52.70 ± 1.60 mg/ml and 75.40 ± 0.80 mg/ml), total phenols (21.45 ± 1.54 mg/ml and 26.50 ± 1.22 mg/ml) for aqueous and ethanol stem bark extracts respectively. The extracts scavenged DPPH radical, reduced Fe3+ and inhibited lipid peroxidation. Doxorubicin significantly (p<0.05) lowered the levels of SOD, CAT, GR and TAS and significantly (p<0.05) but, increased the level of LPO. Oral treatment with Vitex doniana extracts significantly (p<0.05) increased the activities of CAT, GR, SOD and TAS while LPO was significantly (p<0.05) lowered. Vitex doniana stem bark extracts significantly (p<0.05) improved the biochemical derangements observed in the induced untreated animals in comparable manner to that of Silymarin. Conclusion: The present study provides the scientific rationale for the use of Vitex doniana stem bark in traditional medicine and has a viable antioxidative capacity both in vitro and in vivo.

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Xanthine oxidase: evidence against a causative role in renal reperfusion injury

AJP Renal Physiology ◽

10.1152/ajprenal.1990.258.2.f232 ◽

1990 ◽

Vol 258 (2) ◽

pp. F232-F236 ◽

Cited By ~ 5

Author(s):

M. Joannidis ◽

G. Gstraunthaler ◽

W. Pfaller

Keyword(s):

Renal Failure ◽

Acute Renal Failure ◽

Xanthine Oxidase ◽

Time Course ◽

Ischemia Reperfusion ◽

Xanthine Dehydrogenase ◽

Causative Role ◽

Conversion Rates ◽

Ischemic Acute Renal Failure

The conversion rates of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) were compared with the time course of in vivo lipid peroxidation (LPO) in an ischemia-reperfusion model of acute renal failure in the rat. LPO, measured as the renal release of malondialdehyde (MDA), was found to be markedly elevated only during the first 5 min of blood reflow following a 45-min interval of ischemia (arteriovenous MDA difference -277.3 +/- 53.5 vs. 3.7 +/- 5.7 nmol/l in controls, n = 14). After 30 min of reperfusion, arteriovenous MDA differences nearly reached control values (9.7 +/- 31.8 nmol/l, n = 7). In contrast to enhanced LPO, no significant conversion of XDH to XO was found (XO activity in controls: 23 +/- 1% of XO plus XDH activity vs. 26 +/- 3% after 45 min of ischemia, n = 7). Therefore XO-derived superoxide anion radicals cannot be considered causative for LPO in the reperfusion interval of experimental ischemic acute renal failure.

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Sitagliptin-Dependent Differences in the Intensity of Oxidative Stress in Rat Livers Subjected to Ischemia and Reperfusion

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/2738605 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Małgorzata Trocha ◽

Małgorzata Krzystek-Korpacka ◽

Anna Merwid-Ląd ◽

Beata Nowak ◽

Małgorzata Pieśniewska ◽

...

Keyword(s):

Oxidative Stress ◽

Rat Liver ◽

Ischemia Reperfusion ◽

Antioxidant Properties ◽

Thiobarbituric Acid ◽

Treated Group ◽

Paraoxonase 1 ◽

Pon1 Activity ◽

Tbars Level ◽

Rat Livers

Purpose. Ischemia/reperfusion (IR) is the main cause of liver damage after transplantation. We evaluated the effect of sitagliptin (STG) on oxidative stress parameters in the rat liver under IR. Methods. Rats were treated with STG (5 mg/kg) (S and SIR) or saline solution (C and CIR). Livers from CIR and SIR were subjected to ischemia (60 min) and reperfusion (24 h). During reperfusion, aminotransferases (ALT and AST) were determined in blood samples. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), paraoxonase-1 (PON1), glutathione peroxidase (GPx), and the mRNA expression of SOD1 were determined in liver homogenates after reperfusion. Different regions of livers were also histologically evaluated. Results. The PON1 activity was higher, and the TBARS level was lower in SIR than in CIR. There was an inverse relationship between TBARS and PON1 levels in the whole cohort. The GPx activity was lower in ischemic than in nonischemic groups regardless of the STG treatment. In SIR, the SOD1 activity was higher compared to that in CIR. In S, the expression of SOD1 mRNA was the highest of all examined groups and positively correlated with the SOD1 activity in the whole animal cohort. During IR aminotransferases, the activity in the drug-treated group was lower in all examined points of time. In drug-treated groups, the percentage of steatosis was higher than that in nontreated groups regardless of IR. Conclusions. The protective effect of STG on the rat liver, especially its antioxidant properties, was revealed under IR conditions.

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