Minutes Of Reperfusion Research Articles

Effects of hyperoxia and cardiovascular risk factors on myocardial ischemia reperfusion injury: a randomized, sham and placebo controlled parallel study

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Fonds Erasme Recent studies on O2 supplementation in acute coronary syndrome patients are equivocal. We tested the hypothesis that oxidative stress (OS) is increased in rodents with cardiovascular risk factors and enhances ischemia reperfusion injury in the presence of hyperoxia. Forty-three Wistar rats (WR), 30 spontaneous hypertensive rats (SHR) and 33 obese Zucker rats (ZR) were randomized in a sham procedure (1/3rd) or a left anterior descending ligation for 60 minutes (2/3rd). This was followed by 3 hours of reperfusion while animals were randomised either in a hyperoxic (HR) or a normoxic reperfusion group (NR). Baseline troponin (cTnT) was larger in SHR and ZR than WR (both p < 0.001). HR was associated with a lesser troponin rise in SHR and ZR than in NR (both p < 0.001); while the reverse occurred in WR (p < 0.001). In SHR, HR limited total MPO (myeloperoxydase) increase as compared to NR (p = 0.0056) to the contrary of total MPO in WR (p = 0.013). NR was associated with a drastic reduction of total thiols as compared to HR both in SHR and in ZR (both p < 0.001). Despite a heightened baseline OS, HR rather restrained myocardial necrosis and anti/pro-oxidant imbalance in SHR and ZR, to the reverse of healthy WR. Baseline characteristics of the 3 strainWR¹ (n = 41)SHR² (n = 29)ZR³ (n = 33)Age (months)9.0 (7.0 - 10.0)6.0 (6.0 - 8.3) ¹ vs 27.0 (6.0 - 8.0) 1 vs 3, 2 vs 3Weight (mg)590 (553 - 646)436 (419 - 485) ¹ vs 2670 (622 - 716) 2 vs 3Systolic arterial pressure (mmHg)146 (120 - 174)165 (120 - 197)188 (169 - 215) 1 vs 3Heart rate (beat/minute)284 (268 - 310) ¹ vs 2244 (216 - 270)254 (230 - 288) 1 vs 3Troponin T (ng/l)13 (9 - 20)42 (33 - 60) 1vs233 (23 - 53) 2vs3Triglyceride (mg/dl)/87 (64 - 110)1062 (683 - 2459) 2vs3MDA (nmoles)0.10 (0.04)0.09 (0.06)0.14 (0.10) 2vs3Total MPO (ng/ml)2889.7 (932.1)2684.0 (681.7)4479.7 (728.0) 1vs3,2vs3Free total thiols (µM)222.6 (213.9 - 240.5)40.2 (5.3 - 60.2) 1vs282.3 (17.5 - 235.7) 2vs3Abbreviations WR: Wistar rats. SHR: Spontaneous Hypertensive rats. ZR Zucker rats.Both paired t-test and Wilcoxon signed rank test were used. Variables are shown in means with standard deviation (mean (SD)) or in median (interquartile range. IQR). Pairwise test – p < 0.05; 1vs2: WR vs SHR. 1vs3: WR vs ZR. 2vs3: SHR vs ZR.WR were older than the SHR and ZR. ZR were older than SHR. The ZRs were more obese than SHR and more hypertensive than WR. Baseline Troponin T was larger in SHR than ZR and WR. ZR had higher level of triglyceride than SHR. Total MPO was more elevated in ZR than SHR and WR. Oxidative stress was enhanced in ZR than SHR (higher MDA. more elevated total MPO) and total thiols were the lowest in the SHR.Abstract Figure. Troponin T concentration evolution slope

Endothelial Markers: Thrombomodulin and Von Willebrand Factor and Risk of Kidney Thrombosis After Transplantation

Endothelial disturbance is well known as one of the causes of thrombosis. This study measured von Willebrand factor (vWF) and soluble thrombomodulin (sTM) in renal vein blood to evaluate for the risk of thrombosis after kidney transplantation. A cross-sectional study that included 61 consecutive recipients of kidney transplant. The sTM and activity of vWF were evaluated in blood of the renal vein at the time of reperfusion. The renal vein blood had higher values of vWF activity and sTM concentration than the peripheral blood. In the first minutes of reperfusion, the concentration of thrombomodulin was the highest but activity of vWF was the lowest. As the reperfusion continued, thrombomodulin gradually decreased, but vWF increased. The strong correlations of TMs and vWF with warm ischemia were observed (r=0.5577 and r=0.3429, respectively). Thrombosis was found in about 10% of all recipients. However, other complications, such as delayed graft function or ureter necrosis, were associated with high values of vWF and sTM. They were correlated with increased sTM concentration and activity of vWF (P < .006 and P < .05, respectively). This was confirmed by analysis of the receiver operator characteristic curve. The area under the curve values for TMs and vWF were 0.762 and 0.602, respectively (P < .0001 and P < .015, respectively). The cutoff points for sTM and vWF were 14.89 ng/mL and 129.89%, respectively. Positive prediction value sTM and vWF were 76% and 66% and negative prediction value 69% and 59%, respectively. The endothelium of a transplanted kidney could be involved in the pathogenesis of renal thrombosis. Endothelial protection during harvesting can greatly contribute to the improvement of transplantation outcomes. The renal pool of sTM and vWF could be a useful marker of the risk of renal thrombosis.

DSIP-Like KND Peptide Reduces Brain Infarction in C57Bl/6 and Reduces Myocardial Infarction in SD Rats When Administered during Reperfusion.

A structural analogue of the DSIP, peptide KND, previously showed higher detoxification efficacy upon administration of the cytotoxic drug cisplatin, compared to DSIP. DSIP and KND were investigated using the model of acute myocardial infarction in male SD rats and the model of acute focal stroke in C57Bl/6 mice. A significant decrease in the myocardial infarction area was registered in KND-treated animals relative to saline-treated control animals (19.1 ± 7.3% versus 42.1 ± 9.2%). The brain infarction volume was significantly lower in animals intranasally treated with KND compared to the control saline-treated animals (7.4 ± 3.5% versus 12.2 ± 5.6%). Injection of KND in the first minute of reperfusion in the models of myocardial infarction and cerebral stroke reduced infarction of these organs, indicating a pronounced cardioprotective and neuroprotective effect of KND and potentiality for the treatment of ischemia-reperfusion injuries after transient ischemic attacks on the heart and brain, when administered during the reperfusion period. A preliminary pilot study using the model of myocardial infarction with the administration of DSIP during occlusion, and the model of cerebral stroke with the administration of KND during occlusion, resulted in 100% mortality in animals. Thus, in the case of ischemia-reperfusion injuries of the myocardium and the brain, use of these peptides is only possible during reperfusion.

THE IMPACT OF ISCHEMIA-REPERFUSION ON LANGENDORFF RABBIT HEART WITH EXPERIMENTAL ATHEROSCLEROSIS

Abstract Objective: To examine the effect of hypercholesterolemia (HC)on cardiac function in rabbit model. Design and method: 12 adult rabbits divided into 2 groups of 6 rabbits each:Control(C) fed on normal chow, and (HC) fed on 2% cholesterol (Iard mixed with chow) for 16 weeks. After treatment, rabbits from (C) and (HC) groups were sacrificed and hearts were quicky removed, and perfused with standard Krebs Hanseleit buffer at a rate of 10 ml/minute at 37°C, pH 74 in Langendorff retrograde perfusion system at a constant pressure.45 minutes ischemia was followed by 120 minutes reperfusion and parameters of cardiac function: coronary flow (HC), Heart rate (H.R.) and left ventricle developed pressure (LVDP) of hearts from (C) and (HC) groups were measured. TACS DNA laddering kit was used to assess left ventricle cardiomyocytes from group (HC) for apoptosis, also fragments of left ventricle from (HC) were processed for Electron Microscopy (EM). Results: Evaluation of (C.F.), (H.R.) and (LVDP) in (C) and (HC) groups have pointed out a 50% reduction in (C.F). in (HC) group versus (C) during stabilization period In (HC) group, LVDP was depressed during the whole experiment, while in (C) group is was almost constant. Protection of myocardium against oxidative stress was significantly depressed following (HC) treatment, synthesis and utilization of GSH was limited versus (C). Cardiac hypertrophy experimentally induced with (HC) was related with a decrease in (C.F.) and LVDP associated with an increase in lipid peroxidase, in LDH and CK as markers of myocardial lesion and GGT activity in myocardial tissue. Myocyte apoptosis was present in (HC) group, pointed out by DNA laddering pattern on gel electrophoresis. (E.M.) studies have pointed out perinuclear edema of myocytes, dilated sarcoplasmic reticulum and swollen mitochondria. Conclusions: High cholesterol diet in (HC) rabbits induces cardiac hypertrophy and changes in physiological parameters of heart with a negative impact upon synthesis of antioxidant enzymes as well as changes in ultrastructure of heart muscle and at the molecular level (DNA laddering is present as a sign of apoptosis in ventricular myocytes).

PHYSIOLOGICAL AND BIOCHEMICAL STUDIES OF AGEING RAT HEART WITH EXPERIMENTAL ARTERIAL HYPERTENSION

Abstract Objective: It has been shown that DOCA-NaCl dependent arterial hypertension appears before any kidney lesions and there are proofs which suggest the role of NaCl retention or sensitivity to this in etiology of essential arterial hypertension The aim of our study was concerned with evaluation of physiological and biochemical parameters of rat heart with arterial hypertension experimentally induced with (DOCA) as well as to investigate the antioxidant potential and lipid metabolism parameters. Design and method: 16 white male Wistar rats (180 + 20 g), aged 20 months old, fed on standard chew, have been divided into two groups of 8 rats each: group A Controls and group B treated with DOCA for 4 weeks with 2 (i.m.) injections /week) with 10 mg/kg b.w. and two weeks afterwards drinking water has been replaced by saline solution (0.9%NaCl + 0.2%KCl). Evaluation of physiological parameters: heart rate (H.R.), coronary flow (C.F.) and left ventricle systolic pressure (L.V.S.P.) of heart from controls and hypertensive rats has been achieved on isolated heart in Langendorff perfusion system with Krebs Hanseleit bicarbonate buffer at a constant pressure. Oxidative stress has been imposed by applying a 45 minutes ischemia which has been followed by 120 minutes reperfusion. Biochemical studies of antioxidant system have been performed on plasma and left ventricle tissue by evaluating: SOD, GGT, Lipid peroxides, CK, LDH, Cholesterol, LDL, HDL with standard biochemical methods. Results: Our data have pointed out that for about one hour (C.F.) presented higher values as well as (LVSP) and (H.R). in DOCA treated rats, above the values from Controls. These data account for an intense cardiac activity imposed by the onset of arterial hypertension following DOCA treatment. A reduction in GGT in myocardium due to hypoxia generated by cardiac insufficiency following DOCA treatment is accompanied by a reduction of antioxidant potential and both HDL and CK markers of myocardial lesion exhibited higher values. Conclusions: Following 4 weeks DOCA treatment a pathological state is achieved similar with Essential arterial hypertension found in humans, accounted for by the following changes: an intensification of contractile activity, cardiac hypertrophy and the increase in lipid peroxides level, LDH and CK activity.

Composition of Ex Vivo Lung Perfusion Solutions and Kinetics Define Differential Cytokine and Chemokine Secretion in a Porcine Cardiac Arrest Model of Lung Preservation

Purpose Ex vivo lung perfusion is an innovative technique to evaluate marginal lung organs especially after DCD. Normothermic continuous perfusion should reduce ischemic damage and improve the outcome of lung transplantation. However, the optimal protocol for EVLP has not been defined so far. The aim of our study was to compare cytokine/chemokine concentrations in perfusion solutions using different kinetics and solution compounds of EVLP in a porcine cardiac arrest model and to correlate the inflammatory parameters to oxygenation capacity values (∆pO2). Methods Following cardiac arrest and 1h of warm ischemia, lungs were harvested and flushed. Groups were processed as immediate (I-EVLP) 1h cold static preservation (CSP) and delayed (D-EVLP; 9h CSP). D-EVLP lungs were perfused with different solutions: Steen vs. modified Custodiol-N containing dextran (CD) or dextran/albumin (CDA). Cytokine/chemokine levels were analyzed at baseline (0h), after 1h, 4h using multiplex protein arrays. Results Concentrations of TNF-α, IL-6, CXCL8, IFN-γ, IL-1α and IL-1β increased significantly (p Conclusion In a non-heart beating porcine cardiac arrest model with relevant IRI, lungs were perfused with normothermic EVLP. Longer CSP prior to EVLP did not result in enhanced cytokine secretion, but the first hours of reperfusion seem crucial for tissue damage. CD-solution dampens the cytokine/chemokine secretion probably by iron chelators and, possibly, protecting effects of dextran. Addition of albumin had no further effect on inflammation. Cytokine/chemokine concentrations correlated negatively with the oxygenation capacity, an important parameter for organ acceptance. These finding may help to optimize the ex vivo preservation procedure and possibly, more organs could reach the clinically relevant threshold for transplantation, thus, the pool of marginal donor lungs could be enlarged.

Heat Shock Protein 70 Performs as Pharmacological Preconditioning to Protect against Lung Ischemia Reperfusion Injury through Toll-Like Receptor 4 Signaling

Purpose We previously reported that the evidence for a protective role of the innate immune system in lung ischemic preconditioning (IPC), which is mediated a MyD88-independent pathway through TRIF, leading to NF-κB activation also heat shock proteins (HSPs) and protection against lung ischemia-reperfusion (I/R) injury (LIRI). We therefore hypothesized that exogenous HSPs would provide pharmacological preconditioning (PPC). In the present study, we examined whether recombinant HSP70 (rHSP70) in addition to recombinant HSP27 (rHSP27) affected PPC to protect against LIRI. Methods C57BL/6 mice received prHSP27(2.5 mg/kg), which rHSP27 phosphorylated by MAPKAP kinase 2 in vitro, rHSP70 (5.0 mg/kg), or vehicle 30 minutes prior to 60 minutes of ischemia of their left lungs, followed by 180 minutes of reperfusion or IPC with six cycles of 5 minutes ischemia and 5 minutes reperfusion prior to I/R. Response to injury was quantified by tissue MPO activity, vascular permeability, and leukocyte and inflammatory mediator accumulation in BAL expression. Lung homogenates were also analyzed for activation of MyD88, TRIF, NF-κB, and HSP-70. Results In contrast to rHSP27, pretreatment of mice with rHSP70, not phosphorylated in vitro, did result in the development of a significant smaller LIRI, which quantified by vascular permeability, MPO activity, and BAL components when compared with vehicle treated lungs. In the rHSP70 treated group, there was no activation of MyD88 before I/R as in the prHSP27 treated group, however a strong activation of TRIF, NF-κB, also HSP70 was showing before I/R unlike the prHSP27 treated group. Conclusion In this study, we provide evidence for a protective role of the innate immune system in PPC with exogenous HSPs against LIRI. These data also indicate that HSP70, in contrast to HSP27, does not require its phosphorylation to perform protection against LIRI. It suggests that HSP70 may itself play as an agent for PPC through TLR4 signaling pathway.

Abstract P773: Autotaxin and Lysophosphatidic Acid Impair Blood Brain Barrier and Mitochondria Following Ischemic Stroke

Introduction: Ischemic stroke is a leading cause of death and a serious cause of long-term disability in the US. r-TPA is the only treatment available for stroke. Only 5% of patients receive it, as others have the risk of intracerebral hemorrhage. Ischemic reperfusion (I/R) following stroke exacerbates the condition and initiates various molecular signals, ultimately interrupting blood-brain barrier BBB so, better therapy is in need. Lysophosphatidic acid (LPA) is a bioactive lipid regulating various essential cellular functions such as migration, proliferation, adhesion. Autotaxin (ATX) produces LPA, which then regulates through its six G-protein coupled receptors. Methods: Transient middle cerebral artery occlusion (MCAO) with 90 minutes of ischemia and 24 hours of reperfusion was used as a stroke model in mice. LPA was analyzed in plasma with mass spectrometry and in tissue with immunohistochemistry. AR-2 probe fluorescence measured ATX activity. Seahorse analyzer measured the mitochondrial bioenergetics in brain and mouse brain microvascular endothelial cells (MBMEC). Permeability was studied with Electric Cell Substrate Impedance System. Results: ATX was elevated in mRNA level with 1.7 fold increased activity following I/R. LPA showed a significant (P&lt;0.01) increase in the plasma of MCAO mice. LPA in the brain tissue of MCAO mice revealed an increased synthesis of LPA by ATX following I/R injury. Brain mitochondria isolated following I/R injury had significantly (P&lt;0.01) reduced the mitochondrial oxygen consumption rate (OCR). Permeability measured in MBMECs showed LPA treatment increases the permeability. Also, the protein levels of junctional proteins such as βcatenin, Claudin5, VEcadherin, and Zo1 were significantly (P&lt;0.05) decreased with LPA exposure. LPA, as a negative regulator of the BBB, caused permeability through LPA-LPAR1-ROCK dependent pathway. MBMECs show impaired mitochondrial function with decreased OCR and elevated glycolysis towards LPA treatment (P&lt;0.01). Conclusion: We have shown that LPA and its regulator enzyme ATX play a significant role in ischemic stroke, increasing BBB permeability, and elevating mitochondrial dysfunction. ATX inhibitors as therapy could improve the condition of stroke patients.

Expression Pattern of MicroRNA-21 during the Liver Ischemia/Reperfusion.

Ischemia/reperfusion (I/R) injury in cadaveric liver transplantation is not avoidable. Liver I/R injury is an important phenomenon in hepatic damage. MicroRNA-21 (miR-21) plays an important role in I/R injury. The present study aimed to determine the expression pattern of miR-21 in liver I/R injury/recovery and its correlation with the immunologic transmission signals pathways several days post-reperfusion. In an animal model for I/R in the liver, 40 male Balb/c mice were divided into 3 groups. The animals were monitored for 3 and 24 hours, and also for 4, 7, 14, and 28 days post-reperfusion. Liver tissue damage was assessed by histopathology. The plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total antioxidant capacity (TAC) levels were measured with enzymatic assays. MiR-21, programmed cell death 4 (PDCD4) mRNA, T-cell-restricted intracellular antigen 1 (TIA1) mRNA, and fas ligand (FASL) mRNA expression levels were measured; using reverse transcription-polymerase chain reaction (RT-PCR) at different times after the reperfusion in liver tissue and blood. Histopathology and plasma ALT, AST, ALP, and TAC levels confirmed liver damage induced by I/R injury. MiR-21 increased by twofold in the liver tissue and on the inflammatory phase after 24 hours of reperfusion; it then continued to decrease up to day 7 post-reperfusion. Afterward, it continued to rise slightly up to day 14 post-reperfusion. This trend was in parallel with the recovery of the liver damage. MiR-21 expression level in the liver and blood is a predictor of the extent of I/R injury.

A randomized porcine study of the hemodynamic and metabolic effects of combined endovascular occlusion of the vena cava and the aorta in normovolemia and in hemorrhagic shock.

BACKGROUNDMortality from traumatic retrohepatic venous injuries is high and methods for temporary circulatory stabilization are needed. We investigated survival and hemodynamic and metabolic effects of resuscitative endovascular balloon occlusion of the aorta (REBOA) and vena cava inferior (REBOVC) in anesthetized pigs.METHODSTwenty-five anesthetized pigs in normovolemia or severe hemorrhagic shock (controlled arterial bleeding in blood bags targeting systolic arterial pressure of 50 mm Hg, corresponding to 40–50% of the blood volume) were randomized to REBOA zone 1 or REBOA+REBOVC zone 1 (n = 6–7/group) for 45 minutes occlusion, followed by 3-hour resuscitation and reperfusion. Hemodynamic and metabolic variables and markers of end-organ damage were measured regularly.RESULTSDuring occlusion, both the REBOA groups had higher systemic mean arterial pressure (MAP) and cardiac output (p < 0.05) compared with the two REBOA+REBOVC groups. After 60 minutes reperfusion, there were no statistically significant differences between the two REBOA groups and the two REBOA+REBOVC groups in MAP and cardiac output. The two REBOA+REBOVC groups had higher arterial lactate and potassium concentrations during reperfusion, compared with the two REBOA groups (p < 0.05). There was no major difference in end-organ damage markers between REBOA and REBOA+REBOVC. Survival after 1-hour reperfusion was 86% and 100%, respectively, in the normovolemic REBOA and REBOA+REBOVC groups, and 67% and 83%, respectively, in the corresponding hemorrhagic shock REBOA and REBOA+REBOVC groups.CONCLUSIONAcceptable hemodynamic stability during occlusion and short-term survival can be achieved by REBOA+REBOVC with adequate resuscitation; however, the more severe hemodynamic and metabolic impacts of REBOA+REBOVC compared with REBOA must be considered.LEVEL OF EVIDENCEProspective, randomized, experimental animal study. Basic science study, therapeutic.

The Protective Effect of Anthocyanins Extracted from Aronia Melanocarpa Berry in Renal Ischemia-Reperfusion Injury in Mice

Background Our previous research showed the antioxidant activity of anthocyanins extracted from Aronia melanocarpa of black chokeberry in vitro. Ischemia acute kidney injury is a significant risk in developing progressive and deterioration of renal function leading to clinic chronic kidney disease. There were many attempts to protect the kidney against this progression of renal damage. Current study was designed to examine the effect of pretreatment with three anthocyanins named cyanidin-3-arabinoside, cyanidin-3-glucodise, and cyaniding-3-galactoside against acute ischemia-reperfusion injury in mouse kidney. Methods Acute renal injury model was initiated by 30 min clamping bilateral renal pedicle and followed by 24-hour reperfusion in C57Bl/6J mice. Four groups of mice were orally pretreated in 50 mg/g/12 h for two weeks with cyanidin-3-arabinoside, cyanidin-3-glucodise, and cyaniding-3-galactoside and anthocyanins (three-cyanidin mixture), respectively, sham-control group and the renal injury-untreated groups only with saline. Results The model resulted in renal dysfunction with high serum creatinine, blood urea nitrogen, and changes in proinflammatory cytokines (TNF-ɑ, IL-1β, IL-6, and MCP-1), renal oxidative stress (SOD, GSH, and CAT), lipid peroxidation (TBARS and MDA), and apoptosis (caspase-9). Pretreatment of two weeks resulted in different extent amelioration of renal dysfunction and tubular damage and suppression of proinflammatory cytokines, oxidative stress, lipid peroxidation, and apoptosis, thus suggesting that cyanidins are potentially effective in acute renal ischemia by the decrease of inflammation, oxidative stress, and lipid peroxidation, as well as apoptosis. Conclusion the current study provided the first attempt to investigate the role of anthocyanins purified from Aronia melanocarpa berry in amelioration of acute renal failure via antioxidant and cytoprotective effects.

The effect of fucoidin on kidney and lung injury in a rat infrarenal aortic ischemia-reperfusion model.

The aim of this study was to investigate the effects of fucoidin on rat kidney and lung in an infraaortic ishemia reperfusion model. Forty Wistar rats were randomly divided into five groups (n = 8) as sham, control (IR), before ischemia (BI), before reperfusion (BR), and before ischemia and before reperfusion (BI/BR). Rats were subjected to 120 minutes ischemia followed by 120 minutes reperfusion with application of infrarenal aortic clamping. BI received intravenous fucoidin (25 mg/kg) ten minutes before establishing ischemia and BR received ten minutes before reperfusion. BI/BR group received half equal doses of fucoidin both before ischemia (12.5 mg/kg) and reperfusion (12.5 mg/kg) periods, respectively. After sacrification blood and tissue samples were obtained for biochemical (Malondialdehyde (MDA), Nitric oxide (NO), Myeloperoxidase (MPO), Catalase (CAT), Plasma Chitotriosidase (CHIT) and serum ischemia modified albumin (IMA)) and histologic examinations. MDA, NO, MPO, CAT, and IMA levels were lower in BR and BI/BR groups compared to control group (p < 0.001). Plasma CHIT levels in BR and BI/BR groups were lower than in control group (p < 0.05). According to histological examination kidney and lung injury scores were lower in BR and BI/BR groups compared to control group (p < 0.01 and p < 0.001, respectively). The study showed that fucoidin is effective in preventing kidney and lung injury if administered before reperfusion or both before ischemia and reperfusion. However, it has no effect if administered only before ischemia.

The effect of folate on ischemia/reperfusion injury in a rat adnexal torsion model.

The ischemia/reperfusion (I/R) injury of ovaries in adnexal torsion may have inadvertent consequences. Many agents have been studied in terms of their ability to prevent reperfusion damage to ovaries in suspected cases. In this study, folic acid, known to have antioxidative properties, was investigated to determine whether it played a role in the prevention of I/R damage in a rat ovarian torsion model. In this experimental study, 40 female adult Wistar-Albino rats were randomly divided into five groups as control, ischemia, I/R, Fol2 (2mg/kg folic acid), and Fol4 (4mg/kg folic acid). In the Fol2 and Fol4 groups, folic acid was intraperitonelly administered 30min before reperfusion. Blood samples were obtained from the tails of each rat at the second hour of reperfusion. The total oxidant status (TOS), total antioxidant status, cystatin C and folic acid levels of the five groups were investigated. Folic acid in 2mg/kg dose could moderately increase the serum folic acid concentration (15.75-19.95ng/ml, p < 0.05), reduce the level of cystatin C (0.18-0.12μg/L, p < 0.05), and had a tendency to improve the oxidative stress injury (OSI: 76.05-33.06, p > 0.05), although there was no statistical difference in TOS levels (p = 0.07). Folic acid in 4mg/kg dose, could significantly increase the serum folic acid concentration (15.75-37.65ng/ml). However, it did not significantly reduce the level of cystatin C (0.18-0.19μg/L, p > 0.05), and did not improve oxidative stress injury (76.05-130.58, p > 0.05). Folic acid in 2mg/kg dose might improve the ovarian I/R injury though this was not statistically significant. Further studies are required to reach a definitive conclusion about the protective effect of folic acid in I/R injury.

NF-κB and NLRP3 gene expression changes during warm hepatic ischemia-reperfusion in rats with and without silibinin

Aim: This research examined silibinin's anti-inflammatory outcomes on the NOD-like receptor protein-3 (NLRP3) and NF-κB gene expression, which plays a notable role in inciting inflammatory pathways. Background: Hepatic ischemia-reperfusion (I/R) is a common phenomenon in many clinical cases, including liver surgery and transplantation. Inflammatory mediators are vital contributors to the expansion of hepatic damage after I/R injury (I/RI), and therefore, targeting inflammation is a considerable candidate for the management of hepatic I/RI and its complications. Methods: Thirty-two male Wistar rats were divided equally into four groups: 1) Control (Vehicle) group, in which rats underwent laparotomy and received normal saline; 2) SILI group, in which rats underwent laparotomy, and 30 mg/kg silibinin was injected intraperitoneal (IP); 3) I/R group, in which rats underwent I/R and received normal saline; and 4) I/R + SILI group, who encountered I/R after laparotomy and received silibinin. After one hour of ischemia and three hours of reperfusion, blood and liver tissue samples were assembled for future biochemical, histological, and gene expression studies. Results: In vivo analysis attested that serum AST and ALT activities were significantly lessened by silibinin in the SILI + I/R group (p <0.001). Silibinin ameliorated inflammatory liver tissue injuries, including neutrophil and macrophage infiltration, hepatocyte degeneration, cytoplasmic vacuolation, vascular endothelial damages, and sinusoid dilation observed in the I/R group. During I/R, NLRP3 and NF-κB gene expression showed a significant increment compared to the control group (p <0.001), which could be alleviated by silibinin (p <0.01). Conclusion: The results evidence that adjusting the expression of NLRP3 and NF-κB genes during I/R is probably one of the mechanisms of the anti-inflammatory effects of silibinin. Keywords: Ischemia, NF-Κb, NLRP3, Reperfusion, Silibinin. (Please cite as: Zarpou S, Mosavi H, Bagheri A, Malekzadeh Shafaroudi M, Khonakdar-Tarsi A. NF-κB and NLRP3 gene expression changes during warm hepatic ischemia-reperfusion in rats with and without silibinin. Gastroenterol Hepatol Bed Bench 2021;14(3):267-275).

The Influence of Remote Ischemic Conditioning on Focal Brain Ischemia in Rats

Despite obvious progress in the treatment of acute forms of ischemic stroke, the risk of this condition remains unacceptably high. Brain infarction in the middle cerebral artery basin occurs in patients with atherosclerosis. The onset of the brain infarction is facilitated by the cessation of circulation (embolism) in conditions of insufficient collateral circulation. The extent of the infarct zone is determined by neuronal death and impaired microcirculation. The development of new methods for effective targeted restorative stroke therapy is crucial for restorative treatment and reducing the risk of mortality after stroke. Remote ischemic conditioning (RIC) is an approach to limiting reperfusion injury in the ischemic region of the brain after focal ischemia. One of the most commonly used in vivo models in stroke studies is the filament model of Middle Cerebral Artery Occlusion (MCAO) in rats. In our experiment, it was performed for 30 min (J. Koizumi) with subsequent 48-hour reperfusion. Within the first 24 hours after the start of reperfusion several short episodes of ischemia in low limbs were induced. After 48 hours of reperfusion the brains were harvested and stained with TTC. Then we evaluated the effect of RIC within 24 hours ex vivo in rats’ brains, as well as syndecan-1 plasma concentration. Infarct area was assessed by means of Image-Pro program with statistical analysis. Infarct volumes in the model group (31.97% ± 2.5%) were significantly higher compared to the values in the RIC group 48 hours after ischemia-reperfusion (13.6% ± 1.3%) (*P < 0.05). A significant reduction in the area of infarction after RIC is likely due to the effect on the regulation of collateral blood flow in the ischemia area. On the second day after ischemia-reperfusion, tissue swelling was reduced in the RIC group compared to the model group. Analysis of the average concentration of Syndecan-1 revealed the difference between model and RIC groups. Syndecan-1, endothelial glycocalyx protein, might be the regulator which performs vascular control of the interaction with inflammatory cell and is responsible for mediate effect of remote ischemic conditioning on the restriction of ischemic-reperfusion injury.

The effect of dexmedetomidine on gastric ischemia reperfusion injury in rats. Biochemical and histopathological evaluation.

ABSTRACTPurpose:To evaluate the protective effect of dexmedetomidine on gastric injury induced by ischemia reperfusion (I/R) in rats.Methods:A total of 18 male albino Wistar rats were divided groups as: gastric ischemia reperfusion (GIR), gastric ischemia reperfusion and 50 μg/kg dexmedetomidine (DGIR) and sham operation (HG) group. After the third hour of reperfusion, the biochemical and histopathological examinations were performed on the removed stomach tissue.Results:Malondialdehyde (MDA) and myeloperoxidase (MPO) levels were found to be significantly higher in GIR compared to HG (p < 0.05). A statistically significant decrease was observed at the DGIR compared to the GIR for oxidants levels. Total glutathione (tGSH) and superoxide dismutase (SOD) levels were statistically significantly decreased at the GIR, and antioxidants levels were found to be significantly higher in the DGIR (p < 0.05) There was no significant difference between HG and DGIR in terms of SOD (p = 0.097). The DGIRs’ epitheliums, glands and vascular structures were close to normal histological formation.Conclusions:Dexmedetomidine is found to prevent oxidative damage on the stomach by increasing the antioxidant effect. These results indicate that dexmedetomidine may be useful in the treatment of ischemia-reperfusion-related gastric damage.

The Effect of &amp;lt;i&amp;gt;Momordica charantia&amp;lt;/i&amp;gt; on Ovarian Ischemia-Reperfusion

Ovarian torsion is one of the gynecological emergencies that affect ovarian tissue integrity and fertility. In this study, we aim to investigate the effects of Momordica charantia (MC) on ovarian tissue injury induced by ovarian ischemia-reperfusion. Twenty-four rats were assigned to three groups: control group, ischemia-reperfusion (I/R) group and IR + MC group. 600 mg/kg MC extract were given rats via orogastric route. 3-hour ischemia and 3-hour reperfusion were performed for IR protocol. At the end of experiment, ovarian tissues were excised, fixed in zinc-formalin and processed for routine paraffin wax tissue embedding. Sections were stained with hematoxylin and eosin. Ovarian sections of control group showed regular histological appearance. In ovarian sections of I/R group, hemorrhage, fibrin accumulation, mononuclear cell infiltration and degenerated follicles were observed. I/R + MC group showed improved histopathology caused by I/R injury. We think that MC extract may protect ovarian tissue integrity and its histological structures.

The nephroprotective potential of diosgenin against ischemia-reperfusion acute renal damage via suppression of oxidative stress and downregulating inflammatory mediators

ABSTRACT Renal ischemia/reperfusion injury (I/R) is caused by short impairment of the blood supply to the kidney. Acute renal damage (ARD) is still a major problem in today’s clinical practice. Diosgenin (DG), a steroidal sapogenin mainly present infenugreek, yams, Costus species in high amounts. DG as a leading phytoconstituents is beneficial in several disease conditions due to its multifunction including antioxidant, hypolipidemic, anti-inflammatory, hypoglycemic, anticancer and anti-proliferative effects. The purpose of this study was to investigate the nephroprotective potential of DG on ischemia-reperfusion induced kidney damage in rats. Thirty male Wistar rats were divided into five groups. DG was given orally at doses of 20, 40 and 80 mg/kg for 10 days. On day 11th ARD was induced by unilateral ischemia for 45 min followed by 24-hour reperfusion. The levels of creatinine, blood urea nitrogen, total proteins, pro-inflammatory cytokines were decreased in DG + I/R rats compared to NC rats, along with a significant amelioration of oxidative stress. Histopathological analysis exhibited less histological damage in DG + I/R rats as compared with NC rats. Pretreatment of rats with DG (40 and 80 mg/kg) was able to improve these damages significantly, though DG (20 mg/kg) was insignificantly effective. In conclusion, DG proved nephroprotective potential against kidney damage induced by I/R injury via mitigation of inflammation, oxidative stress, and histopathologic injuries.

Protective effect of cordycepin on experimental renal ischemia/reperfusion injury in rats.

To date, various molecules have been investigated to reduce the effect of renal ischemia/reperfusion (I/R) injury. However, none have yet led to clinical use. The present study aimed to investigate the protective effect of cordycepin (C) on renal I/R injury in an experimental rat model. Twenty-four mature Sprague Dawley female rat was randomly divided into three groups: Sham, I/R, I/R+C. All animals underwent abdominal exploration. To induce I/R injury, an atraumatic vascular bulldog clamp was applied to the right renal pedicle for 60 minutes (ischemia) and later clamp was removed to allow reperfusion in all rats, except for the sham group. In the I/R + C group, 10 mg/kg C was administered intraperitoneally, immediately after reperfusion. After 4 hours of reperfusion, the experiment was terminated with right nephrectomy. Histological studies and biochemical analyses were performed on the right nephrectomy specimens. EGTI (endothelial, glomerular, tubulointerstitial) histopathology scoring and semi-quantitative analysis of renal cortical necrosis were used for histological analyses and superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), total oxidant status (TOS) for biochemical analyses. Histopathological examination of the tissue damage revealed that all kidneys in the sham group were normal. The I/R group had higher histopathological scores than the I/R + C group. In the biochemical analysis of the tissues, SOD, MDA, TOS values were found to be statistically different in the I/R group compared to the I/R + C group (p: 0.004, 0.004, 0.001 respectively). Intraperitoneal cordycepin injection following ischemia preserve renal tissue against oxidative stress in a rat model of renal I/R injury.

Optimum marker selection of acute liver damage in rats in the experiment

Relevance. Assessment of liver damage and functional state is one of the leading tasks of clinical and laboratory diagnostics. Traditionally used methods for determining the activity of a number of indicator enzymes in blood with relative organ-specificity, such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, sorbitol dehydrogenase, alkaline phosphatase, and -glutamyl transferase, have low specificity for liver diseases. In this regard, the determination of the optimal marker of acute liver injury is an urgent problem. Aim. The purpose of the study is to determine the dynamics of changes in liver damage markers in rats at different periods of reperfusion after 20 minutes of ischemia in order to select the indicators that most informatively characterize the state of test-animals under conditions of correction of ischemia-reperfusion syndrome. Materials and methods: the study was performed on 120 white nonlinear male rats weighing 200250 grams. The animals were divided into 8 groups of 15 test-animals; all of them were simulated liver ischemia by clamping the analog of the hepatoduodenal ligament with a vascular clamp for 20 minutes. Then, blood was taken from different groups of rats at different reperfusion times 5, 15, 30, 60, 120, 180 minutes, 8 hours and a day. In the blood plasma of laboratory animals, the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), glutathione transferase (GST), and lactate concentration were determined. Results: the results obtained allowed us to characterize two main peaks of indicators: a 5-minute period after restoration of blood flow the maximum activity of glutathione transferase and lactate concentration, increased by 3.94.7 times; 60180 minutes of reperfusion is the peak of aminotransferase activity, a significant increase in the activity of which begins 60 minutes after the restoration of blood flow and reaches its maximum by the 3rd hour of reperfusion, and LDH, the peak of which is recorded already by the 60th minute of revascularization. At the same time, after 8 hours of reperfusion, an obvious tendency for a decrease in all studied parameters was determined, which ends a day after modeling ischemia with a decrease to the level of control values. Conclusion: the assessment of organ damage in the ischemic period and the anti-ischemic effect of metabolic drugs can be carried out with the determination of an increase in lactate concentration and glutathione transferase activity almost immediately after restoration of blood flow. The development of injuries during the reperfusion period is more expedient to assess by determining AST, ALT and LDH after a 3-hour period of blood flow restoration, at which time the maximum values of markers are recorded under the condition of 20-minute total liver ischemia.