Reperfusion Period Research Articles

The effect of leg ischemia/reperfusion injury on the liver in an experimental breast cancer model

Background/Aim: Ischemia/reperfusion (I/R) injury occurs during breast cancer surgery, especially those involving a modified radical mastectomy, lumpectomy, and axillary lymph node dissection. Tissue damage and stress due to I/R alter immune system functions, especially those of the myeloid cells. The immunologic impact of this I/R injury on myeloid-derived cancerous cells remains unknown. We sought to investigate the effect of I/R injury in the extremity close the breast tumor location on myeloid cell population in the liver and liver metastasis. Methods: 4T1 breast tumors were created in the left inguinal breast region of the experimental animals. When the tumor reached 0.5 cm in diameter, ischemia was produced on the left down-extremity for 90 min and reperfusion was induced for short (3 days), middle (7 days), and long terms (14 days). At the end of the reperfusion period, proximal limbs and livers were harvested. The limb and liver samples were histopathologically examined with H&E staining. Immune cell percentages were determined in the liver by flow cytometry. Results: There was an increase in muscle fiber degeneration and disorganization in the I/R induced proximal legs on days 3 and 7 of I/R in both tumor free and tumor bearing animals with a further impact in tumor bearing mice. Even though I/R injury did not affect tumor metastasis to the liver, it had an impact on liver myeloid cell percentages in both tumor free and tumor bearing animals. Additionally, tumor bearing mice demonstrated higher myeloid cell percentages in both the pre-I/R and post-I/R experimental groups. There was a remarkable change in the levels of granulocytic, and monocytic myeloid cells and macrophages due to the I/R injury. Conclusion: With the formation of short-term I/R injury in a distant site, tumor development and/or seeding to metastasis sites after surgery could be prevented. This study contributes to the understanding of the inflammatory process after I/R injury occurring during interventions.

Quercetin enhances the efficacy of telmisartan in myocardial ischaemia/reperfusion injury in rats

Abstract Background The clinical outcome of myocardial ischaemia/reperfusion (I/R) injury is still unpredictable and detrimental despite the use of several agents including renin-angiotensin system inhibitors. Quercetin (QN), one of the most prevalent flavonoids, has attracted great attention in the recent years due to its protective role against I/R injury. Interestingly, a recent experimental study showed an important role for β-catenin in the regulation of myocardial I/R injury following heterotopic heart transplantation. Purpose The present investigation was directed to estimate the role GSK-3β/β-catenin signaling as a possible mechanistic pathway, through which QN could modulate the therapeutic effect of telmisartan (Tel) in myocardial I/R injury in rats. Methods Myocardial I/R was induced by ligation of the left descending coronary artery for 30 min followed by reperfusion for 2 h. Rats were pretreated with Tel (12 mg/kg/day, po), QN (25 mg/kg/day) or a combination of both agents for 3 days before the experiment. Electrocardiographic abnormalities were assessed at the end of ischemic and reperfusion periods. Animals were then sacrificed to assess the cardiac injury surrogate markers; viz., serum CK-MB and cTn-I levels and cardiac energy content (ATP) as well as oxidative stress (ROS, MDA, SOD and TAC), inflammation-related (TNF-α, NF-κB, ICAM-1 and MPO) and apoptotic markers (caspase 3 and Bcl-2). Moreover, the hallmark of fibrosis (TGF-β1) was estimated in addition to GSK-3β/β-catenin signaling. Finally, histological examinations were performed to assess the severity of myocardial damage. Results Combined Tel/QN therapy showed an additional improvement compared to each therapy alone (p<0.05) toward reducing myocardial I/R-induced oxidative stress, inflammatory, fibrogenic, and apoptotic markers which subsequently restored Wnt/β-catenin signaling through inhibition of GSK-3β upregulation together with spiking up of β-catenin content. All these changes were associated with restoration of myocardial energy content and prevention of I/R-induced damage in histological examination. Funding Acknowledgement Type of funding sources: None.

Cerebroprotective effect of Aloe Emodin: In silico and in vivo studies

This study involved cerebroprotective potential of aloe emodin (AE) by in silico molecular docking analysis against various cerebrotoxic proteins followed by in vivo activity on multiple occlusions and reperfusion of bilateral carotid arteries (MO/RCA) induced cerebral injury in experimental rats. Molecular docking studies were carried out to evaluate the binding affinity (or binding interaction) between AE and various proteins involved in apoptosis such as caspase-3 (CASP3) and Bcl-2-associated X protein (BAX), and proteins involved in inflammation such as interleukin-6 (IL-6), tumor necrosis factor α (TNF α), nitric oxide synthase (NOS), acid-sensing ion channel (ASIC) and glutamate receptor (GR) involved in cerebral stroke, and results were compared with that of standard drugs, minocycline, quercetin, and memantine. Cerebral ischemic reperfusion induced by MO/RCA was assessed for 10 mins reperfusion period as one cycle, and the experiment was conducted for up to 3 cycles in rats. After completion of 3 cycles, the rats were subjected to ethically acceptable animal euthanasia followed by isolation of the brains which were studied for the size of cerebral infarction, and biochemical parameters such as glutathione (GSH), malondialdehyde (MDA), catalase (CAT) were estimated from the brain homogenate. Further, histological studies were done to study neuronal contact. Results of molecular docking indicated that the AE exhibited interaction with active sites of cerebrotoxic proteins usually involved in protein functions or cerebrotoxicity. Biochemical results showed that in the untreated brain, MDA levels increased significantly, and decreased GSH and CAT levels were observed when compared to MO/RCA group, while treated rats showed a decrease in the levels of MDA and an increase in GSH and CAT levels as compared to MO/RCA rats. In comparison with sham rats and normal rats, histopathological analysis revealed neuronal damage in MO/RCA surgery rats which manifested as decreased intact neurons. However, treatment with AE 50 mg/kg b.wt. restored contact between neuronal cells. It can be concluded that AE showed cerebroprotective effect on RO/RCA with promising inhibition of cerebrotoxic proteins (apoptotic and neuroinflammatory) as evident from molecular docking studies. The cerebroprotective potential of AE could be due to its anti-inflammatory, antioxidant, and antiapoptotic principles.

Oxygen Saturation and Postoperative Mortality in Patients With Acute Ischemic Stroke Treated by Endovascular Thrombectomy.

Monitored anesthesia care (MAC) and general anesthesia (GA) with endotracheal intubation are the 2 most used techniques for patients with acute ischemic stroke (AIS) undergoing endovascular thrombectomy. We aimed to test the hypothesis that increased arterial oxygen concentration during reperfusion period is a mechanism underlying the association between use of GA (versus MAC) and increased risk of in-hospital mortality. In this retrospective cohort study, data were collected at the Cleveland Clinic between 2013 and 2018. To assess the potential mediation effect of time-weighted average oxygen saturation (Spo2) in first postoperative 48 hours between the association between GA versus MAC and in-hospital mortality, we assessed the association between anesthesia type and post-operative Spo2 tertiles (exposure-mediator relationship) through a cumulative logistic regression model and assessed the association between Spo2 and in-hospital mortality (mediator-outcome relationship) using logistic regression models. Confounding factors were adjusted for using propensity score methods. Both significant exposure-mediator and significant mediator-outcome relationships are needed to suggest potential mediation effect. Among 358 patients included in the study, 104 (29%) patients received GA and 254 (71%) received MAC, with respective hospital mortality rate of 19% and 5% (unadjusted P value <.001). GA patients were 1.6 (1.2, 2.1) (P < .001) times more likely to have a higher Spo2 tertile as compared to MAC patients. Patients with higher Spo2 tertile had 3.8 (2.1, 6.9) times higher odds of mortality than patients with middle Spo2 tertile, while patients in the lower Spo2 tertile did not have significant higher odds compared to the middle tertile odds ratio (OR) (1.8 [0.9, 3.4]; overall P < .001). The significant exposure-mediator and mediator-outcome relationships suggest that Spo2 may be a mediator of the relationship between anesthetic method and mortality. However, the estimated direct effect of GA versus MAC on mortality (ie, after adjusting for Spo2; OR [95% confidence interval {CI}] of 2.1 [0.9-4.9]) was close to the estimated association ignoring Spo2 (OR [95% CI] of 2.2 [1.0-5.1]), neither statistically significant, suggesting that Spo2 had at most a modest mediator role. GA was associated with a higher Spo2 compared to MAC among those treated by endovascular thrombectomy for AIS. Spo2 values that were higher than the middle tertile were associated with higher odds of mortality. However, GA was not significantly associated with higher odds of death. Spo2 at most constituted a modest mediator role in explaining the relationship between GA versus MAC and mortality.

Protective effects of 17β-oestradiol on coagulation and systemic inflammation after total occlusion of the descending aorta in male rats.

The surgical treatment for diseases of the descending aorta is related to a high mortality rate because of the activation of a systemic inflammatory process due to ischaemia and reperfusion (I/R) injury. Activation of coagulation can contribute to the inflammatory process, resulting in microcirculatory damage and multiple organ failure. Our goal was to evaluate the role of prophylactic intravenous 17β-oestradiol (E2) in coagulation, the inflammatory response and hepatic injury after occlusion of the descendent proximal aorta in male rats. Wistar male rats were randomized and allocated to 3 groups (n = 8 per group): sham, surgically manipulated; IR, animals subjected to I/R; and E2, animals treated with E2 (280 µg/kg, intravenously) before I/R. I/R was induced by insertion of a 2-Fr Fogarty arterial embolectomy catheter in the descending aorta, which was occluded for 20 min, followed by a reperfusion period of 2 h. Serological markers, platelet aggregation, hepatic vascular flow, systemic and liver inflammatory response and apoptosis were analysed. The coagulation process was evaluated by thromboelastometry. The aortic occlusion led to a reduction in plasma fibrinogen concentration in parallel with increased clotting time, greater clot firmness and reduced lysis. E2 treatment was able to increase fibrinogen, prevent the increase in clotting time and normalize clot firmness, but it exerted only a mild effect on clot lysis. Platelet aggregation was increased by IR, and E2 treatment was able to reduce it. There was a reduction in flow percentage in the IR group that was not prevented by E2. In parallel, higher aggregate formation was observed in the vessels of the IR group of animals. There was increased systemic release of interleukin-1-β, interleukin-6 and interleukin-10 in the IR group, which was reduced in the treated animals. The current results suggest that pretreatment with E2 before an ischaemic period induced by occlusion of the proximal descending aorta is effective in preventing alterations in coagulation and systemic inflammation due to I/R injury.

Protective role of melatonin and spirulina in aortic occlusion-reperfusion model in rats.

The aim of this experiment was to investigate the role of melatonin and spirulina on multiorgan damage induced by ischemia/reperfusion injury (IR) in a rat model. A total of 32 male rats weighing 200-220 g were allocated into 4 groups (n = 8/group) (Sham, Control-IR [CIR], Melatonin-IR [MIR], and Spirulina-IR [SIR]). Sham group underwent midline laparotomy and dissection of the aorta without injury. In other groups, an IR model was established by clamping (ischemia) and releasing (reperfusion) the abdominal aorta at the supraceliac level for 20 min. All rats were given 3 ml/kg of distilled water by gavage for 14 days before and 7 days after the experiment. The treatment groups received either melatonin (50 mg/kg) or spirulina (50 mg/kg) by the same route. On the 21st day of the experiment, the rats were sacrificed. We found that melatonin and spirulina ameliorated the effects of IR at different levels of significance (ranging from p = .01 to p < .001), increasing total antioxidant capacity (TAC) and superoxide dismutase levels, and decreasing total oxidant status, oxidative stress index (OSI), myeloperoxidase, tumor necrosis factor-alfa and malondialdehyde levels. When compared MIR and SIR groups, only TAC and OSI levels did differ in favor of melatonin between the groups (p < .05). Histopathological and immunohistochemical examinations showed that melatonin and spirulina similarly reduced IR-related tissue damage and apoptosis. We concluded that melatonin and spirulina may have a protective role against oxidative tissue damage and apoptosis in the abdominal aortic IR animal model. PRACTICAL APPLICATIONS: Coarctation of aorta (CoA) and interrupted aortic arch (IAA) are serious cardiac defects with high morbidity and mortality if not diagnosed and treated early in life. Restoration of blood flow in CoA or IAA through prostaglandin E1 infusion, angioplasty or surgery can cause ischemia/reperfusion (IR) injury. This reperfusion period may be complicated IR injury at remote organs. It may be beneficial to increase antioxidant capacity in preventing stress-induced tissue damage. Melatonin and spirulina are agents with strong antioxidant properties. In this animal research, protective role of these products on multiorgan damage induced by IR was investigated for the first time. We found that both melatonin and spirulina ameliorate the effects of IR to varying degrees. This study provides evidence that melatonin and spirulina may have preventive effects on oxidative tissue damage and apoptosis in the abdominal aortic IR animal model.

Cardioprotective effect of eicosapentaenoic acid during ischemia and reperfusion

Objective : In this work, rats isolated hearts were infused EPA before the ischemia period and during reperfusion for available get well in parameter relatives to redox reactions. Methods : The effect of EPA was tested on isolated hearts induced to ischemia and reperfusion, treatment occurred at different times (ischemia or reperfusion). Antioxidant capacity against peroxyl radicals, glutathione cysteine ligase activity, glutathione concentration, lactate dehydrogenase, and creatine kinase concentration was analyzed. Results : Hearts treated with eicosapentaenoic acid had the minor generation of species reactive oxygen and lipid damage after reperfusion. The GSH concentration was higher when the hearts were treated with eicosapentaenoic acid in the period of reperfusion. Conclusion : In conclusion, this study demonstrates that the dose of EPA (20μM) used before ischemia can act as a cardioprotective antioxidant molecule, prevented damage heart from ischemic and reperfusion injury.

Prophylactic effect of ethyl pyruvate on renal ischemia/reperfusion injury in rats

Background: Following our hypothesis that oxidative stress might play a primary role in renal ischemia/reperfusion injury (RIRI), we investigated if ethyl pyruvate (EPy) with potent antioxidant activity might prevent or alleviate RIRI induced in rats. Methods: Sprague-Dawley rats were randomly divided into four groups: (A) Sham, (B) renal ischemia/reperfusion (RIR), (C) RIR with EPy supplement (RIR+EPy), and (D) RIR with Mann supplement (RIR+Mann). Mannitol (Mann), a preoperative agent being clinically used, was tested for comparison with EPy. Rats were subjected to 40-min ischemia, followed by 24-h reperfusion. Either EPy or Mann was given to rats 30 min prior to ischemia and immediately before the reperfusion period. Results: The RIR and RIR+Mann groups showed palpable kidney injuries with the ~5-fold elevated blood urea nitrogen (BUN) and creatinine (Cr) levels, indicating renal dysfunction. However, the kidneys in the RIR+EPy group appeared merely normal (similar to the Sham’s) with the basal BUN/Cr levels, indicating normal renal function. No effects on histology, BUN or Cr were yet seen with Mann. Moreover, specific kidney injury markers were up-regulated and oxidative stress was also ~2.1-fold severer in the RIR group, whereas little changes in those markers and oxidative stress were seen with EPy supplement (RIR+EPy). Conclusions: Although oxidative stress feasibly plays a key role in RIRI, EPy with antioxidant activity is capable of protecting the kidneys from such an assault. Thus, EPy (not Mann) should be considered as an effective perioperative renoprotective agent that could be used clinically.

Molar Sodium Lactate Attenuates the Severity of Postcardiac Arrest Syndrome: A Preclinical Study.

To determine whether continuous IV infusion of molar sodium lactate would limit cardiac arrest-induced neurologic injury and cardiovascular failure. Randomized blinded study (animal model). University animal research facility. Twenty-four adult male "New Zealand White" rabbits. Anesthetized rabbits underwent 12.5 minutes of asphyxial cardiac arrest and were randomized to receive either normal saline (control group, n = 12) or molar sodium lactate (molar sodium lactate group, n = 12) at a rate of 5 mL/kg/hr during the whole 120-minute reperfusion period. Pupillary reactivity (primary outcome), levels of S100β protein, in vitro brain mitochondria functions, cardiovascular function, and fluid balance were assessed. Molar sodium lactate reduced brain injury, with a higher proportion of animals exhibiting pupillary reactivity to light (83% vs 25% in the CTRL group, p = 0.01) and lower S100β protein levels (189 ± 42 vs 412 ± 63 pg/mL, p < 0.01) at the end of the protocol. Molar sodium lactate significantly prevented cardiac arrest-induced decrease in oxidative phosphorylation and mitochondrial calcium-retention capacity compared with controls. At 120 minutes of reperfusion, survival did not significantly differ between the groups (10/12, 83% in the molar sodium lactate group vs nine of 12, 75% in the control group; p > 0.99), but hemodynamics were significantly improved in the molar sodium lactate group compared with the control group (higher mean arterial pressure [49 ± 2 vs 29 ± 3 mm Hg; p < 0.05], higher cardiac output [108 ± 4 vs 58 ± 9 mL/min; p < 0.05], higher left ventricle surface shortening fraction [38% ± 3% vs 19% ± 3%; p < 0.05], and lower left ventricular end-diastolic pressure [3 ± 1 vs 8 ± 2 mm Hg; p < 0.01]). While fluid intake was similar in both groups, fluid balance was higher in control animals (11 ± 1 mL/kg) than that in molar sodium lactate-treated rabbits (1 ± 3 mL/kg; p < 0.01) due to lower diuresis. Molar sodium lactate was effective in limiting the severity of the postcardiac arrest syndrome. This preclinical study opens up new perspectives for the treatment of cardiac arrest.

Interruption of endolysosomal trafficking leads to stroke brain injury

Background and purposeDysfunction of the endolysosomal system can cause cell death. A key molecule for controlling the endolysosomal trafficking activities is the N-ethylmaleimide-sensitive factor (NSF) ATPase. This study investigates the cascades of NSF ATPase inactivation events, endolysosomal damage, cathepsin release, and neuronal death after focal brain ischemia. MethodsA total of 62 rats were used in this study. They were subjected to sham surgery or 2 h of focal brain ischemia followed by 1, 4, and 24 h of reperfusion. Confocal microscopy and Western blot analysis were utilized to analyze the levels, redistribution, and co-localization of key proteins of the Golgi apparatus, late endosomes, endolysosomes, and lysosomes. Light and electron microscopy were used to examine the histopathology, protein aggregation, and endolysosomal ultrastructures. ResultsTwo hours of focal brain ischemia in rats led to acute neuronal death at the striatal core in 4 h and a slower type of neuronal death in the neocortical area during 1–24 h reperfusion periods. Confocal microscopy showed that NSF immunoreactivity was irreversibly and selectively depleted from most, if not all, post-ischemic penumbral neurons. Western blot analysis further demonstrated that NSF depletion from brain sections was due to its deposition into dense inactive aggregates that could not be recognized by the NSF antibody. Commitantly, the Golgi apparatus was completely fragmented and cathepsin B (CTSB)-containing endolysosomal structures, as well as p62/SQSTM1- and EEA1-immunopositive structures were massively accumulated in the post-ischemic penumbral neurons. Ultimately, CTSB was released into the cytoplasm and extracellular space, causing stroke brain injury. ConclusionStroke Inactivates NSF, resulting in disruption of the reforming of functional endolysosomal compartments, blockade of the endocytic and autophagic pathways, a large scale of CTSB release into the cytoplasm and extracellular space, and stroke brain injury in the rat model.

Long-term cold storage preservation does not affect fatty livers from rats fed with a methionine and choline deficient diet

BackgroundWaiting lists that continue to grow and the lack of organs available for transplantation necessitate the use of marginal livers, such as fatty livers. Since steatotic livers are more susceptible to damage from ischemia and reperfusion, it was investigated whether fatty livers with different lipidomic profiles show a different outcome when subjected to long-term cold storage preservation.MethodsEight-week-old male Wistar rats fed for 2 weeks by a methionine-choline-deficient (MCD) diet or control diet were employed in this study. Livers were preserved in a University of Wisconsin (UW) solution at 4 °C for 6, 12 or 24 h and, after washout, reperfused for 2 h with a Krebs-Henseleit buffer at 37 °C. Hepatic enzyme release, bile production, O2-uptake, and portal venous pressure (PVP) were evaluated. The liver fatty acid profile was evaluated by a gas chromatography-mass spectrometry (GC/MS).ResultsMCD rats showed higher LDH and AST levels with respect to the control group. When comparing MCD livers preserved for 6, 12 or 24 h, no differences in enzyme release were found during both the washout or the reperfusion period. The same trend occurred for O2-uptake, PVP, and bile flow. A general decrease in SFA and MUFA, except for oleic acid, and a decrease in PUFA, except for arachidonic, eicosadienoic, and docosahexanaeoic acids, were found in MCD rats when compared with control rats. Moreover, the ratio between SFA and the various types of unsaturated fatty acids (UFA) was significantly lower in MCD rats.ConclusionsAlthough prolonged cold ischemia negatively affects the graft outcome, our data suggest that the quality of lipid constituents could influence liver injury during cold storage: the lack of an increased hepatic injury in MCD may be justified by low SFA, which likely reduces the deleterious tendency toward lipid crystallization occurring under cold ischemia.

Induction of ischemic tolerance by remote perconditioning or postconditioning as neuroprotective strategy for spinal cord motor neurons

AimsThe study is focused on the investigation of the mechanisms leading to ischemic tolerance acquisition in the spinal cord neurons via application of non-invasive method of remote conditioning. Material and methodsWe have verified the possibility of neuroprotection of spinal cord in rabbit by using remote perconditioning (PerC) applied during last 12 min of spinal cord ischemia (SC-ischemia) or postconditioning (PostC) applied after 1st (early) or 3rd (late) h of reperfusion. Spinal cord ischemia was induced by occlusion of the aorta below the left renal artery for 20 min. Reperfusion period was 24 or 72 h. Remote conditioning was induced by compression of left forelimb with a tourniquet in 3 cycles of 2 min of ischemia, each followed by 2 min of reperfusion. Damaged neurons were detected by Fluoro Jade B method and the modified Tarlov score was used for functional assessment. Key findingsThe remote conditioning significantly attenuated degeneration of motor neurons in all remote conditioned groups versus both SC-ischemia groups. We detected significant changes in number of Hsp70 positive motor neurons. At 72time point, in the group with remote late PostC we observed significant increase (p < 0.001) of Hsp70 positive motor neurons versus SC- ischemia group and sham control. There was a trend towards improvement of hindlimbs movement. SignificanceThis study showed the effectiveness of remote conditioning as a neuroprotective strategy, evidenced by induction of ischemic tolerance leading to decrease of motor neuron degeneration.

Effect of ATP and molsidomine combination on contractile function of isolated adult and old rat hearts during adequate coronary perfusion, at ischemia and reperfusion

Abstract. Pathology of the cardiovascular system occupies a major place in the structure of diseases of the elderly and old patients. Metabolic disturbances are very important in ischemic damages of myocardium in the elderly and old people. So, drugі with metabolic mechanism of action is very ppromising in the treatment of elderly patients with cardiovascular diseases. The relevance of this study is determined by the feasibility of using drugs of metabolic action, which have a beneficial effect on the metabolism of cardiomyocytes, improve blood supply to the myocardium, increase its contractile function. The effect of ATP-molsidomine combination on myocardial contractility in different age animals was stuiesy in vitro experiments. The experiments on the isolated hearts from adult and old rats have shown that combined use of ATP and molsidomine did not significantly affect the contractility of the isolated hearts of adult rats under different perfusion regimes. In old rats, the use of ATP-molsidomine combination had a positive effect on the contractile function of the myocardium under the influence of damaging factors (ischemia, reperfusion): prevented a decrease of left ventricular developing pressure and its first derivative (velocity of pressure rise and velocity of pressure decline) and accelerated its growth during reperfusion. Co-administration of ATP and molsidomine during ischemia had a positive effect on the heart rhythm and restored heart rate at the reperfusion period in adult and old rats. The results of the study indicate a positive effect of the ATP-molsidomine combination on the myocardial contractility in old rats. Combined use of ATP and molsidomine exerted a favourable influence on the heart rhythm under damaging factors both in the adult and old animals. Key words: ATP; molsidomine; isolated rat heart; myocardial contractility; ageing

Study to elucidate the pharmacological activity of retinalamin in a rat model of ischemic retinopathy

Introduction: Over the past few years, the incidence of retinal ischemic disorders has been increasing, due to a rising prevalence of such socially burdensome diseases as diabetes and hypertension, which ultimately lead to ocular vascular pathology. The identification of new treatment options that would prevent retinal neuron death is a crucial task of modern pharmacology.&#x0D; Materials and methods: The research was carried out on male Wistar rats. Retinopathy was modeled by inducing a 30-min ischemic episode, with a 72-hour period of reperfusion and subsequent administration of Retinalamin and Emoxypine for 10 days. The effectiveness of the drugs was evaluated by electroretinographic, ophthalmoscopic and morphological assessments.&#x0D; Results and discussion: On Day 14 of the experiment, a dose-dependent preservation of the electroretinogram b-wave/a-wave amplitude ratio was observed in the animals treated with Retinalamin depending on a dose (1.39±0.06, 1.46±0.03 and 1.49±0.04 in low (0.214 mg/kg), medium (0.428 mg/kg) and high (0.857 mg/kg) Retinalamin dose groups, respectively). The ophthalmoscopic picture of the fundus oculi also improved following the treatment with Retinalamin (1.42, 1.69 and 1.90 times lower ophthalmoscopic scores compared to placebo-treated animals in low, medium and high dose groups, respectively). The morphologic “coefficient of change” applied to ganglion cell layer was 2.2, 1.7 and 1.6 points in low, medium and high dose Retinalamin groups, respectively. These results are significantly different from both intact and placebo group (p&lt;0.05). Based on the aforementioned experimental findings, we conclude that Retinalamin has a retinoprotective effect and is superior to the drug of comparison (Emoxypine).&#x0D; Conclusion: The greatest neuroprotective effects were shown in the groups receiving Retinalamin. In these groups, the ERG b-wave/a-wave amplitude ratio was preserved, the ophthalmoscopic picture was less pathologic and retinal morphology features were close to those of the intact retina.

Hypertrophic preconditioning attenuates post-myocardial infarction injury through deacetylation of isocitrate dehydrogenase 2.

Ischemic preconditioning induced by brief periods of coronary occlusion and reperfusion protects the heart from a subsequent prolonged ischemic insult. In this study we investigated whether a short-term nonischemic stimulation of hypertrophy renders the heart resistant to subsequent ischemic injury. Male mice were subjected to transient transverse aortic constriction (TAC) for 3 days followed aortic debanding on D4 (T3D4), as well as ligation of the left coronary artery to induce myocardial infarction (MI). The TAC preconditioning mice showed markedly improved contractile function and significantly reduced myocardial fibrotic area and apoptosis following MI. We revealed that TAC preconditioning significantly reduced MI-induced oxidative stress, evidenced by increased NADPH/NADP ratio and GSH/GSSG ratio, as well as decreased mitochondrial ROS production. Furthermore, TAC preconditioning significantly increased the expression and activity of SIRT3 protein following MI. Cardiac-specific overexpression of SIRT3 gene through in vivo AAV-SIRT3 transfection partially mimicked the protective effects of TAC preconditioning, whereas genetic ablation of SIRT3 in mice blocked the protective effects of TAC preconditioning. Moreover, expression of an IDH2 mutant mimicking deacetylation (IDH2 K413R) in cardiomyocytes promoted myocardial IDH2 activation, quenched mitochondrial reactive oxygen species (ROS), and alleviated post-MI injury, whereas expression of an acetylation mimic (IDH2 K413Q) in cardiomyocytes inactivated IDH2, exacerbated mitochondrial ROS overload, and aggravated post-MI injury. In conclusion, this study identifies TAC preconditioning as a novel strategy for induction of an endogenous self-defensive and cardioprotective mechanism against cardiac injury. Therapeutic strategies targeting IDH2 are promising treatment approaches for cardiac ischemic injury.

Increased nitric oxide availability worsens the cardiac performance during early re-perfusion period in adult rats.

Re-perfusion is the standard therapy for acute myocardial infarction, despite the associated pathologies that may contribute to irreversible myocardial injury. The present study aims to clarify the alterations in cardiac activities in response to experimental cardiac ischemic arrest followed by re-perfusion in isolated hearts perfused with nitric oxide (NO) donor, l-arginine, or NO inhibitor, Nω-Nitro-l-arginine methyl ester hydrochloride (l-NAME), to shed light on the possible role of NO in the re-perfusion process. Hearts isolated from adult Wistar rats were studied on Langendorff preparation under basal conditions and during 30min re-perfusion following 30min of total global ischemia. Rats were randomly divided into three groups; control and l-arginine or l-NAME infused heart groups. Cardiac tissue content of malondialdhyde, catalase and nitrite was also measured. Compared to the control group, both l-arginine and l-NAME infused hearts showed increased basal chronotropy and myocardial flow rate. Following ischemia and during the whole period of re-perfusion, the three groups demonstrated significant deterioration in the inotropic activity and compromised myocardial flow rate. l-arginine infused hearts revealed depressed inotropy and chronotropy, weak systolic and diastolic functions with compromised myocardial flow at early 5min of re-perfusion, yet with significantly higher myocardial flow rate by the end of re-perfusion. Reducing NO availability by l-NAME revealed mild impact on the ischemia re-perfusion induced contractile dysfunction, whereas excess NO worsens cardiac performance at the early re-perfusion period.

Combined assessment of intestinal viability using laser doppler flowmetry and laser fluorescence spectroscopy

Introduction. The development of an objective non-invasive method for intraoperative assessment of intestinal viability remains urgent for modern surgery. In this context, the method of laser fluorescence spectroscopy (LFS) of coenzymes of oxidative metabolism, as well as a combination of this technique with the simultaneous use of laser Doppler flowmetry (LDF) seems promising. Materials and methods. The model of ischemia-reperfusion of the small intestine of 4 Californian Rabbits was used to study the relationship of the parameters of LFS and LDF with the histological picture. A model of intraoperative ischemia was used by temporarily clamping the trunk of the cranial mesenteric vascular bundle for 90 min, followed by intraoperative and postoperative reperfusion for 60 minutes and 24 hours, respectively. LDF and LFS data were recorded from intestine at the end of the intraoperative reperfusion period. 24 hours after the surgery, the animals were subjected to histologic evaluation of intestine ischemic changes, which were compared with the LDF and LFS data. Diagnostic value of LDF and LFS, and their combination for intraoperative assessment of intestinal viability were analyzed. Results. A significant correlation was found between the parameters of LDF, LFS and the degree of ischemic changes according to the histological data. The method of isolated assessment of the difference in the fluorescence of reduced nicotin adenine dinucleotide (NADH) before and after ischemia-reperfusion (77.3 %) has the greatest diagnostic value. The method has the highest sensitivity with a combination of differences in LDF and LFS values before and after ischemia-reperfusion (85.7 %) (P&lt;0.05). Conclusions. LFS, as well as its combination with LDF, is a useful method for objective assessment of intestinal viability, which requires further research and has potential for clinical use.

Effects of hypothermia and pentoxifylline on the adnexal torsion/detorsion injuries in a rat testis model.

This study was designed to investigate the effects of separate and combined administration of hypothermia and pentoxifylline to preserve the effects on the testicles in an experimental model of testicular torsion/ detorsion injuries in rats. Forty male adult Wistar rats were randomly divided into five groups, control, torsion/detorsion (TD), torsion/detorsion/hypothermia (TD+ICE), torsion/detorsion received of pentoxifylline (40mg/kg, ip) (TD+PTX) and torsion/detorsion/hypothermia/PTX (TD+ICE+PTX). Left testicular torsion (TT) was performed for 4 and half hours, and ice fragments have been used at the beginning of torsion. After the reperfusion period (a week), oxidative maker's serum levels, testosterone hormone, sperm parameters, and histopathological and gene expression evaluations have been performed. Significant adverse changes were observed in the TD group for histological variables, sperm count, oxidative marker, testosterone hormone, Bax, BCL2 and caspase-3 expression. The parameters studied in the group receiving PTX improved in comparison with the TD group, while macroscopical parameters of both the hypothermia and PTX+ICE groups were not different compared with the TD group. The results revealed that PTX, as an antioxidant component, was protective against testicular torsion, while hypothermia and hypothermia plus PTX did not exhibit this property, which may have been due to the duration of hypothermia (4hr) or reperfusion period.

Toll-Like Receptor 4 Activation Prevents Rat Cardiac Fibroblast Death Induced by Simulated Ischemia/Reperfusion.

Death of cardiac fibroblasts (CFs) by ischemia/reperfusion (I/R) has major implications for cardiac wound healing. In in vivo models of myocardial infarction, toll-like receptor 4 (TLR4) activation has been reported as a cardioprotector; however, it remains unknown whether TLR4 activation can prevent CF death triggered by simulated I/R (sI/R). In this study, we analyzed TLR4 activation in neonate CFs exposed to an in vitro model of sI/R and explored the participation of the pro-survival kinases Akt and ERK1/2. Simulated ischemia was performed in a free oxygen chamber in an ischemic medium, whereas reperfusion was carried out in normal culture conditions. Cell viability was analyzed by trypan blue exclusion and the MTT assay. Necrotic and apoptotic cell populations were evaluated by flow cytometry. Protein levels of phosphorylated forms of Akt and ERK1/2 were analyzed by Western blot. We showed that sI/R triggers CF death by necrosis and apoptosis. In CFs exposed only to simulated ischemia or only to sI/R, blockade of the TLR4 with TAK-242 further reduced cell viability and the activation of Akt and ERK1/2. Preconditioning with lipopolysaccharide (LPS) or treatment with LPS in ischemia or reperfusion was not protective. However, LPS incubation during both ischemia and reperfusion periods prevented CF viability loss induced by sI/R. Furthermore, LPS treatment reduced the sub-G1 population, but not necrosis of CFs exposed to sI/R. On the other hand, the protective effects exhibited by LPS were abolished when TLR4 was blocked and Akt and ERK1/2 were inhibited. In conclusion, our results suggest that TLR4 activation protects CFs from apoptosis induced by sI/R through the activation of Akt and ERK1/2 signaling pathways.

The Beneficial influence of Rosemary Aqueous Extract on the treatment of oxidative stress-induced myocardial Ischemia in Rats. Z. H. AL-Qaisi1, S. M. Abbood1, M. T. Mohammed *1, S. M. Kadhim2 1Department of Chemistry, College of Science, Mustansiriya University, Iraq 2Ministry of Education, Rusafa-1, Iraq *Corresponding author: dr.mustafa@uomustansiriyah.edu.iq

Abstract Ischemia “stroke” may occur in various combinations of clinical illnesses. The effects of such an Ischemic represent a serious problem. Oxidative stress has been shown to act as one of the main causes of Myocardial Ischemia- Reperfusion Injury (IR). Reperfusion injury is defined as the action of returning the flow of blood to an organ or tissue after a period of stroke or myocardial infarction (MI). R. Officinalis (Rosemary) has a diverse therapeutic against many illnesses. Further, recent evidence also gives R. Officinalis a major role in protecting diverse organs from harmful oxidative stress. So, R.Officinalis seems like a good protect to the myocardial against the IR Injury. The study included the components of essential oils of the rosemary leaves in the watery extract and determine whether rosemary protects form Ischemia-Reperfusion induced myocardial ischemia. We divided forty-five Wister rats into three groups Group 1 as the control group, Group 2 underwent surgery without extract therapy, and Group 3 with extract therapy. Wister rats in Group 2, and Group 3 underwent myocardial ischemia for 45 min followed by 90 min period of Reperfusion. Animals in group 3 received rosemary (1 mL/g) for 14 days also, before Ischemia, and before Reperfusion. We found that the extract comprises from many essential oils. The levels of cardiac markers (AST, ALT, and LDH) and Oxidative stress markers (NO, and LPO) in group 3 a significantly decreased compared to group 2. Based on the results, the R.Officinalis treatment lessens the effect of Ischemia-Reperfusion on the rat’s heart, including the induce myocardial infarction.