8-11-14-eicosatrienoic-acid and Reperfusion-Injury

Knowledge regarding the plasma fatty acid (FA) pattern in patients with liver cirrhosis is fragmentary.. We evaluated plasma FA lipidome and its association with the prognosis of cirrhosis and severity of liver graft damage after transplantation.. In this observational study, plasma FA lipidome was investigated in 51 cirrhotic patients before liver transplantation and in 90 age- and sex-matched healthy control subjects. In addition, we studied ischemia-reperfusion damage in the liver of 38 patients for whom a graft biopsy was available at transplantation. With the use of logistic regression, we modeled the presence of cirrhosis, the dichotomized model for end-stage liver disease score below and above the median, and the presence of severe liver graft ischemia-reperfusion damage.. The FA pattern was markedly altered in cirrhotic patients, who showed, compared with healthy controls, higher monounsaturated FAs, lower n-6 and n-3 polyunsaturated FAs, and undetectable cerotic acid. Plasma di-homo-γ-linolenic acid was independently associated with the presence of cirrhosis (OR: 0.026; 95% CI: 0.004, 0.196; P < 0.0001), severity of its prognosis (OR: 0.041; 95% CI:0.005, 0.376; P = 0.006), postreperfusion graft hepatocellular necrosis (OR: 0.921; 95% CI: 0.851, 0.997; P = 0.043), and sinusoidal congestion (OR: 0.954; 95% CI: 0.912, 0.998; P = 0.039). Associations of di-homo-γ-linolenic acid with the presence of cirrhosis and severity of its prognosis were confirmed also after false discovery rate correction.. Cerotic and di-homo-γ-linolenic acids may serve as markers of disease and prognosis in liver cirrhosis. Dietary supplementation with di-homo-γ-linolenic acid could be a reasonable interventional strategy to delay disease progression in liver cirrhosis.

Topics: 8,11,14-Eicosatrienoic Acid; Adolescent; Aged; Biomarkers; Cohort Studies; Fatty Acids; Female; Graft Survival; Humans; Liver; Liver Cirrhosis; Liver Transplantation; Logistic Models; Male; Middle Aged; Necrosis; Prognosis; Reperfusion Injury; Severity of Illness Index; Young Adult

To investigate the effect of 14,15-EET on the parthanatos in neurons induced by cerebral ischemia and reperfusion, middle cerebral artery occlusion and reperfusion (MCAO/R) and oxygen glucose deprivation/reoxygenation (OGD/R) were used to simulate cerebral ischemia reperfusion in vivo and in vitro, respectively. TTC staining and the Tunel method were used to detect cerebral infarct volume and neuronal apoptosis. Western blot and immunofluorescence were used to detect poly (ADP-ribose) polymerase-1 (PARP-1) activation and AIF nuclear translocation. The production of reactive oxygen species (ROS) and the expression of antioxidant genes were detected by Mito SOX, DCFH-DA and qPCR methods. MCAO/R increased cerebral infarct volume and neuronal apoptosis in mice, while 14,15-EET pretreatment increased cerebral infarct volume and neuronal apoptosis. OGD/R induced reactive oxygen species generation, PARP-1 cleavage, and AIF nuclear translocation in cortical neurons. 14,15-EET pretreatment could enhance the antioxidant gene expression of glutathione peroxidase (GSH-Px), heme oxygenase-1 (HO-1) and superoxide dismutase (SOD) in cortical neurons after ischemia and reperfusion. 14,15-EET inhibits the neuronal parthanatos induced by MCAO/R through upregulation of the expression of antioxidant genes and by reducing the generation of reactive oxygen species. This study advances the EET neuroprotection theory and provides a scientific basis for targeted clinical drugs that reduce neuronal parthanatos following cerebral ischemia and reperfusion.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Brain Injuries; Brain Ischemia; Disease Models, Animal; Glucose; Male; Mice; Models, Biological; Neurons; Neuroprotective Agents; Oxidative Stress; Parthanatos; Reactive Oxygen Species; Reperfusion Injury

Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert anti-inflammatory, anti-apoptotic, pro-proliferative, and antioxidant effects on the cardiovascular system. However, the role of CYP2J2 and EETs in pulmonary arterial hypertension (PAH) with lung ischemia-reperfusion injury (LIRI) remains unclear. In the present study, we investigated the effects of CYP2J2 overexpression and exogenous EETs on PAH with LIRI in vitro and in vivo.. CYP2J2 gene was transfected into rat lung tissue by recombinant adeno-associated virus (rAAV) to increase the levels of EETs in serum and lung tissue. A rat model of PAH with LIRI was constructed by intraperitoneal injection of monocrotaline (50 mg/kg) for 4 weeks, followed by clamping of the left pulmonary hilum for 1 h and reperfusion for 2 h. In addition, we established a cellular model of human pulmonary artery endothelial cells (HPAECs) with TNF-α combined with anoxia/reoxygenation (anoxia for 8 h and reoxygenation for 16 h) to determine the effect and mechanism of exogenous EETs.. CYP2J2 overexpression significantly reduced the inflammatory response, oxidative stress and apoptosis associated with lung injury in PAH with LIRI. In addition, exogenous EETs suppressed inflammatory response and reduced intracellular reactive oxygen species (ROS) production and inhibited apoptosis in a tumor necrosis factor alpha (TNF-α) combined hypoxia-reoxygenation model of HPAECs. Our further studies revealed that the anti-inflammatory effects of CYP2J2 overexpression and EETs might be mediated by the activation of PPARγ; the anti-apoptotic effects might be mediated by the PI3K/AKT pathway.. CYP2J2 overexpression and EETs protect against PAH with LIRI via anti-inflammation, anti-oxidative stress and anti-apoptosis, suggesting that increased levels of EETs may be a promising strategy for the prevention and treatment of PAH with LIRI.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Cells, Cultured; Cytochrome P-450 CYP2J2; Disease Models, Animal; Gene Expression Regulation; Humans; Hypertension, Pulmonary; Male; Rats; Reperfusion Injury; RNA

Imbalances in cytochrome P450 (CYP)-dependent eicosanoid formation may play a central role in ischemic acute kidney injury (AKI). We reported previously that inhibition of 20-hydroxyeicosatetraenoic acid (20-HETE) action ameliorated ischemia/reperfusion (I/R)-induced AKI in rats. Now we tested the hypothesis that enhancement of epoxyeicosatrienoic acid (EET) actions may counteract the detrimental effects of 20-HETE and prevent the initiation of AKI.. Male Lewis rats underwent right nephrectomy and ischemia was induced by 45 min clamping of the left renal pedicle followed by up to 48 h of reperfusion. Circulating CYP-eicosanoid profiles were compared in patients who underwent cardiac surgery with (n = 21) and without (n = 38) developing postoperative AKI.. Ischemia induced an about eightfold increase of renal 20-HETE levels, whereas free EETs were not accumulated. To compensate for this imbalance, a synthetic 14,15-EET analogue was administered by intrarenal infusion before ischemia. The EET analogue improved renal reoxygenation as monitored by in vivo parametric MRI during the initial 2 h reperfusion phase. The EET analogue improved PI3K- as well as mTORC2-dependent rephosphorylation of Akt, induced inactivation of GSK-3β, reduced the development of tubular apoptosis and attenuated inflammatory cell infiltration. The EET analogue also significantly alleviated the I/R-induced drop in creatinine clearance. Patients developing postoperative AKI featured increased preoperative 20-HETE and 8,9-EET levels.. Pharmacological interventions targeting the CYP-eicosanoid pathway could offer promising new options for AKI prevention. Individual differences in CYP-eicosanoid formation may contribute to the risk of developing AKI in clinical settings.

Topics: 8,11,14-Eicosatrienoic Acid; Acute Kidney Injury; Animals; Cardiac Surgical Procedures; Fatty Acids; Humans; Hydroxyeicosatetraenoic Acids; Ischemia; Kidney; Male; Postoperative Complications; Rats; Rats, Inbred Lew; Reperfusion Injury; Signal Transduction

Neuronal apoptosis mediated by the mitochondrial apoptosis pathway is an important pathological process in cerebral ischemia-reperfusion injury. 14,15-EET, an intermediate metabolite of arachidonic acid, can promote cell survival during ischemia/reperfusion. However, whether the mitochondrial apoptotic pathway is involved this survival mechanism is not fully understood. In this study, we observed that infarct size in ischemia-reperfusion injury was reduced in sEH gene knockout mice. In addition, Caspase 3 activation, cytochrome C release and AIF nuclear translocation were also inhibited. In this study, 14,15-EET pretreatment reduced neuronal apoptosis in the oxygen-glucose deprivation and re-oxygenation group in vitro. The mitochondrial apoptosis pathway was also inhibited, as evidenced by AIF translocation from the mitochondria to nucleus and the reduction in the expressions of cleaved-caspase 3 and cytochrome C in the cytoplasm. 14,15-EET could reduce neuronal apoptosis through upregulation of the ratio of Bcl-2 (anti-apoptotic protein) to Bax (apoptosis protein) and inhibition of Bax aggregation onto mitochondria. PI3K/AKT pathway is also probably involved in the reduction of neuronal apoptosis by EET. Our study suggests that 14,15-EET could suppress neuronal apoptosis and reduce infarct volume through the mitochondrial apoptotic pathway. Furthermore, the PI3K/AKT pathway also appears to be involved in the neuroprotection against ischemia-reperfusion by 14,15-EET.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Apoptosis; Cytochromes c; Male; Mice, Inbred C57BL; Mitochondria; Phosphatidylinositol 3-Kinases; Reperfusion Injury; Signal Transduction

Epoxyeicosatrienoic acid (EET) has wide applications due to the unique biological effects of anti‑hyperlipidemia, inhibition of platelet aggregation, anti‑inflammation, anti‑cancer, anti‑lipid oxidation and the promotion of brain tissue development. The present study investigated whether EET ameliorates cerebral ischemia‑reperfusion injury (CIRI) by inhibiting inflammatory factors and pannexin. Specific pathogen‑free 7‑week‑old male Sprague‑Dawley rats were randomly divided into three groups: Sham, CIRI and EET. Neurological deficit scores, cerebral infarct volume and cerebral edema were assessed in CIRI rats. Enzyme‑linked immunosorbent assays were performed to detect tumor necrosis factor‑α, interleukin‑6, nuclear factor‑κB and inducible nitric oxide synthase (iNOS) levels, and western blot analysis was performed also used to assess cleaved caspase‑3, phospholipase A2 (PLA2), cyclooxygenase‑2 and prostaglandin E2 (PGE2) protein expression levels. EET ameliorated cerebral injury and CIRI‑induced cleaved caspase‑3 protein expression levels in rats. EET additionally suppressed CIRI‑induced inflammation reactions and iNOS protein expression in rats. Furthermore, the protein expression levels of PLA2, PGE2 and pannexin‑1 in CIRI rats were inhibited by treatment with EET. These results indicated that EET reduces CIRI by inhibiting inflammation and levels of cleaved caspase‑3, PLA2, PGE2 and pannexin-1.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Brain Ischemia; Caspase 3; Connexins; Cyclooxygenase 2; Cytokines; Dinoprostone; Disease Models, Animal; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Fatty Acids, Unsaturated; Interleukin-6; Male; Nerve Tissue Proteins; NF-kappa B; Nitric Oxide Synthase Type II; Phospholipases A2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tumor Necrosis Factor-alpha

Acute kidney injury (AKI) causes severe morbidity and mortality for which new therapeutic strategies are needed. Docosahexaenoic acid (DHA), arachidonic acid (ARA), and their metabolites have various effects in kidney injury, but their molecular mechanisms are largely unknown. Here, we report that 14 (15)-epoxyeicosatrienoic acid [14 (15)-EET] and 19 (20)-epoxydocosapentaenoic acid [19 (20)-EDP], the major epoxide metabolites of ARA and DHA, respectively, have contradictory effects on kidney injury in a murine model of ischemia/reperfusion (I/R)-caused AKI. Specifically, 14 (15)-EET mitigated while 19 (20)-EDP exacerbated I/R kidney injury. Manipulation of the endogenous 19 (20)-EDP or 14 (15)-EET by alteration of their degradation or biosynthesis with selective inhibitors resulted in anticipated effects. These observations are supported by renal histological analysis, plasma levels of creatinine and urea nitrogen, and renal NGAL. The 14 (15)-EET significantly reversed the I/R-caused reduction in glycogen synthase kinase 3β (GSK3β) phosphorylation in murine kidney, dose-dependently inhibited the hypoxia/reoxygenation (H/R)-caused apoptosis of murine renal tubular epithelial cells (mRTECs), and reversed the H/R-caused reduction in GSK3β phosphorylation in mRTECs. In contrast, 19 (20)-EDP dose-dependently promoted H/R-caused apoptosis and worsened the reduction in GSK3β phosphorylation in mRTECs. In addition, 19 (20)-EDP was more metabolically stable than 14 (15)-EET in vivo and in vitro. Overall, these epoxide metabolites of ARA and DHA function conversely in I/R-AKI, possibly through their largely different metabolic stability and their opposite effects in modulation of H/R-caused RTEC apoptosis and GSK3β phosphorylation. This study provides AKI patients with promising therapeutic strategies and clinical cautions.

Topics: 8,11,14-Eicosatrienoic Acid; Acute Kidney Injury; Animals; Blood Urea Nitrogen; Creatinine; Docosahexaenoic Acids; Gene Expression Regulation; Glycogen Synthase Kinase 3 beta; Humans; Kidney Tubules; Lipocalin-2; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Reperfusion Injury; Signal Transduction; Survival Analysis

Epoxyeicosatrienoic acids (EETs), the cytochrome P450 epoxygenase metabolite of arachidonic acid, have been demonstrated to have neuroprotective effect. Phosphatidylinositol 3-kinase (PI3K)/Akt and ATP-sensitive potassium (KATP) channels are thought to be important factors that mediate neuroprotection. However, little is known about the role of PI3K/Akt and KATP channels in brain after EETs administration. In vitro experiment, oxygen-glucose deprivation (OGD) was performed in cultured rat cerebral microvascular smooth muscle cells (SMCs) for 4 h. The effect of 14,15-EET on OGD induced cell apoptosis was examined after reoxygenation. Western blot and real-time PCR were used to analyze the expression of Kir6.1, SUR2B (two subunits of KATP channels) and p-Akt on cerebral microvascular SMCs. In vivo experiments, we use 12-(3-adamantan-1-yl-ureido)-dodecanoic acid [AUDA, a specific soluble epoxide hydrolase (sEH) inhibitor] to confirm the effect of EETs indirectly. Rats were injected intraperitoneally with AUDA before being subjected to middle cerebral artery occlusion (MCAO). We detected the apoptosis and the expression of p-Akt, Kir6.1 and SUR2B in ischemic penumbra. The results showed that EETs protect against cerebral ischemia/reperfusion (I/R) injury and upregulated the expression of p-Akt and Kir6.1 in both of ischemic penumbra and OGD induced cerebral microvascular SMCs. The protective effect was inhibited by Wortmannin (a specific PI3K inhibitor) and Glib (a specific KATP inhibitor) respectively in vitro experiment. In conclusion, these results suggested that the protective effect of EETs on cerebral I/R injury is associated with PI3K/Akt pathway and KATP channels. Furthermore, the PI3K pathway may contribute to mediating KATP channels on cerebral microvascular SMCs.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Brain Injuries; Cell Survival; Cells, Cultured; Hypoxia, Brain; KATP Channels; Male; Neuroprotective Agents; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Vasodilator Agents

Injurious inflammatory response is critical to the development of lung ischemia/reperfusion injury (LIRI). The cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert an anti-inflammatory effect on the cardiovascular system. We therefore cytochrome hypothesized that CYP2J2 overexpression and pretreatment with exogenous EETs may have the potential to reduce LIRI.. A rat model was used to mimic the condition of LIRI by clamping the left pulmonary hilum for 60 minutes, followed by reperfusion for 2 hours. Moreover, we developed a cell model using human pulmonary artery endothelial cells by anoxia for 8 hours, followed by reoxygenation for 16 hours to determine the anti-inflammatory effect and mechanism of CYP2J2 overexpression and exogenous 11,12-EET.. Lung ischemia/reperfusion increased lung wet/dry and lung weight/body weight ratios, protein concentration in bronchoalveolar lavage fluid and concentrations of pro-inflammatory, including mediators in serum IL-1β, IL-8, TNF-α, sP- and sE-selectin, and decreased concentration of anti-inflammatory mediator IL-10. Ischemia/reperfusion also leaded to pulmonary edema and inflammation under light microscopy. Furthermore, activation of NF-κB p65 and degradation of IκBα were remarkably increased in ischemia/reperfusion lung tissues. While CYP2J2 overexpression significantly inhibited the above effects (p<0.05). In vitro data further confirmed the anti-inflammatory effect of CYP2J2 overexpression and 11,12-EET, an effect that may probably be mediated by PPARγ activation.. CYP2J2 overexpression and administration of exogenous EETs can protect against LIRI via anti-inflammatory effects. This can be a novel potential strategy for prevention and treatment of LIRI.

Topics: 8,11,14-Eicosatrienoic Acid; Anilides; Animals; Anti-Inflammatory Agents; Cell Hypoxia; Cell Line; Cytochrome P-450 CYP2J2; Cytochrome P-450 Enzyme System; Cytokines; Down-Regulation; E-Selectin; Humans; I-kappa B Proteins; Inflammation Mediators; Intercellular Adhesion Molecule-1; Lung; Male; NF-KappaB Inhibitor alpha; P-Selectin; PPAR gamma; Rats; Rats, Transgenic; Rats, Wistar; Reperfusion Injury; Transcription Factor RelA

Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acids to epoxyeicosatrienoic acids (EETs). EETs exert various biological effects, including anti-inflammatory, anti-apoptotic, pro-proliferation, pro-angiogenesis, anti-oxidation, and anti-fibrosis effects. However, little is known about the role of CYP2J2 and EETs in lung ischemia/reperfusion injury. In this study, we examined the effects of exogenous EETs or CYP2J2 overexpression on lung ischemia/reperfusion injury in vivo and in vitro.. CYP2J2 gene was stably transfected into rat lungs via pcDNA3.1-CYP2J2 plasmid delivery, resulting in increased EETs levels in the serum and lung. A rat model of lung ischemia/reperfusion injury was developed by clamping the left lung hilum for 1 hour, followed by reperfusion for 2 hours. We found that CYP2J2 overexpression markedly decreased the levels of oxidative stress and cell apoptosis in lung tissues induced by ischemia/reperfusion. Moreover, we observed that exogenous EETs, or CYP2J2 overexpression, enhanced cell viability, decreased intracellular reactive oxygen species (ROS) generation, inhibited mitochondrial dysfunction, and attenuated several apoptotic signaling events in a human pulmonary artery endothelial cells (HPAECs)-based anoxia/reoxygenation model. These apoptotic events included activation of NADPH oxidase, collapse of mitochondrial transmembrane potential, and activation of pro-apoptotic proteins and caspase-3. These effects were mediated, at least partially, by the PI3K/Akt signaling pathway.. These results reveal that CYP2J2 overexpression and exogenous EETs can protect against oxidative stress and apoptosis following lung ischemia/reperfusion in vivo and in vitro, suggesting that increasing the level of EETs may be a novel promising strategy to prevent and treat lung ischemia/reperfusion injury.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Apoptosis; Blotting, Western; Cell Hypoxia; Cell Survival; Cells, Cultured; Cytochrome P-450 CYP2J2; Cytochrome P-450 Enzyme System; Endothelial Cells; Flow Cytometry; Humans; Lung; Male; Membrane Potential, Mitochondrial; Oxidative Stress; Oxygen; Protective Agents; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury

We previously demonstrated that 11,12 and 14,15-epoxeicosatrienoic acids (EETs) produce cardioprotection against ischemia-reperfusion injury in dogs and rats. Several signaling mechanisms have been implicated in the cardioprotective actions of the EETs; however, their mechanisms remain largely elusive. Since nitric oxide (NO) plays a significant role in cardioprotection and EETs have been demonstrated to induce NO production in various tissues, we hypothesized that NO is involved in mediating the EET actions in cardioprotection. To test this hypothesis, we used an in vivo rat model of infarction in which intact rat hearts were subjected to 30-min occlusion of the left coronary artery and 2-hr reperfusion. 11,12-EET or 14,15-EET (2.5mg/kg) administered 10min prior to the occlusion reduced infarct size, expressed as a percentage of the AAR (IS/AAR), from 63.9±0.8% (control) to 45.3±1.2% and 45.5±1.7%, respectively. A nonselective nitric oxide synthase (NOS) inhibitor, L-NAME (1.0mg/kg) or a selective endothelial NOS inhibitor, L-NIO (0.30mg/kg) alone did not affect IS/AAR but they completely abolished the cardioprotective effects of the EETs. On the other hand, a selective neuronal NOS inhibitor, nNOS I (0.03mg/kg) and a selective inducible NOS inhibitor, 1400W (0.10mg/kg) did not affect IS/AAR or block the cardioprotective effects of the EETs. Administration of 11,12-EET (2.5mg/kg) to the rats also transiently increased the plasma NO concentration. 14,15-EET (10μM) induced the phosphorylation of eNOS (Ser(1177)) as well as a transient increase of NO production in rat cardiomyoblast cell line (H9c2 cells). When 11,12-EET or 14,15-EET was administered at 5min prior to reperfusion, infarct size was also reduced to 42.8±2.2% and 42.6±1.9%, respectively. Interestingly, L-NAME (1.0mg/kg) and a mitochondrial KATP channel blocker, 5-HD (10mg/kg) did not abolish while a sarcolemmal KATP channel blocker, HMR 1098 (6.0mg/kg) and a mitochondrial permeability transition pore (MPTP) opener, atractyloside (5.0mg/kg) completely abolished the cardioprotection produced by the EETs. 14,15-EET (1.5mg/kg) with an inhibitor of MPTP opening, cyclosporin A (CsA, 1.0mg/kg) produced a greater reduction of infarct size than their individual administration. Conversely, an EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE, 2.5mg/kg) completely abolished the cardioprotective effects of CsA, suggesting a role of MPTP in mediating the EET actions. Taken together, these results

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Cell Line; Heart; Hemodynamics; Imines; Male; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Infarction; Nitric Oxide; Nitric Oxide Synthase Type III; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Epoxyeicosatrienoic acids (EETs) are protective in both myocardial and brain ischemia, variously attributed to activation of K(ATP) channels or blockade of adhesion molecule upregulation. In this study, we tested whether EETs would be protective in lung ischemia-reperfusion injury.. The filtration coefficient (K(f)), a measure of endothelial permeability, and expression of the adhesion molecules vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) were measured after 45 minutes ischemia and 30 minutes reperfusion in isolated rat lungs.. K(f) increased significantly after ischemia-reperfusion alone vs time controls, an effect dependent upon extracellular Ca(2+) although not on the EET-regulated channel TRPV4. Inhibition of endogenous EET degradation or administration of exogenous 11,12- or 14,-15-EET at reperfusion significantly limited the permeability response to ischemia-reperfusion. The beneficial effect of 11,12-EET was not prevented by blockade of K(ATP) channels nor by blockade of TRPV4. Finally, 11,12-EET-dependent alteration in adhesion molecules expression is unlikely to explain its beneficial effect, since the expression of the adhesion molecules VCAM and ICAM in lung after ischemia-reperfusion was similar to that in controls.. EETs are beneficial in the setting of lung ischemia-reperfusion, when administered at reperfusion. However, further study will be needed to elucidate the mechanism of action.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Capillary Permeability; Cell Adhesion Molecules; Endothelium, Vascular; In Vitro Techniques; Lung; Lung Injury; Rats; Reperfusion Injury; TRPV Cation Channels; Vascular Cell Adhesion Molecule-1

1 This study examined the contribution of cytochrome P450 metabolites of arachidonic acid in mediating ischaemia/reperfusion (I/R)-induced cardiac dysfunction in normal and diabetic rats. 2 We first compared the metabolism of arachidonic acid in microsomes prepared from the hearts of control rats and rats treated with streptozotocin (55 mg kg(-1)) to induce diabetes. The production of dihydroxyeicosatrienoic acids and epoxyeicosatrienoic acids (EETs) were similar in microsomes prepared from the hearts of control and diabetic rats, but the production of 20-hydroxyeicosatetraenoic acid (20-HETE) was two-fold higher in diabetic hearts than in control animals. 3 We then compared the change in left ventricular pressure (P(max)), left ventricular end-diastolic pressure, coronary flow and coronary vascular resistance in isolated perfused hearts obtained from control and diabetic animals after 40 min of global ischaemia (I) followed by 30 min of reperfusion (R). The decline in cardiac function was three- to five-fold greater in the hearts obtained from diabetic vs. control animals. 4 Pretreatment of the hearts with N-hydroxy-N'-(4-butyl-2-methyl-phenyl)-formamidine (HET0016, 1 microm), a selective inhibitor of the synthesis of 20-HETE, for 30 min before I/R resulted in significant improvement in the recovery of cardiac function in the hearts obtained from diabetic but not in control rats. Perfusion with an inhibitor of soluble epoxide hydrolase, 1-cyclohexyl-3-dodecyl urea (CDU), before I/R improved the recovery of cardiac function in hearts obtained from both control and diabetic animals. Perfusion with both HET0016 and CDU resulted in significantly better recovery of cardiac function of diabetic hearts following I/R than that seen using either drug alone. Pretreatment of the hearts with glibenclamide (1 microm), an inhibitor of ATP-sensitive potassium channels, attenuated the cardioprotective effects of both CDU and HET0016. 5 This is the first study to suggest that acute blockade of the formation of 20-HETE and/or reduced inactivation of EETs could be an important strategy to reduce cardiac dysfunction following I/R events in diabetes.

Topics: 8,11,14-Eicosatrienoic Acid; Amidines; Animals; Arachidonic Acid; Blood Glucose; Body Weight; Coronary Circulation; Cytochrome P-450 Enzyme System; Diabetes Mellitus, Experimental; Enzyme Inhibitors; Epoxide Hydrolases; Glyburide; Heart; Hydroxyeicosatetraenoic Acids; Male; Microsomes; Myocardium; Rats; Rats, Wistar; Reperfusion Injury; Urea; Vascular Resistance; Ventricular Dysfunction, Left

To investigate the effects of 11, 12-epoxyeicosatrienoic acids (11, 12-EET) on the degree of hypoxia/reoxygenation injury in human umbilical vein endothelial cells ( HUVECs), and reveal the possible pathway of EET on protection.. Primary cultured HUVECs were randomly divided into control group, hypoxia/reoxygenation group, 11, 12-EET control group, 11, 12- EET hypoxia/reoxygenation group, inhibition of extracellular signal-regulated kinase (ERKI/2) group, and inhibition of nitric oxide synthase (NOS) group. Hypoxia/reoxygenation injury model in HUVECs was established by exposure to hypoxia (2% O2, 5% CO2 and 93% N2) for 3 hours, followed by reoxygenation (95% air and 5% CO2) for 1 hour. The evaluation of the endothelial cells were made by immunohistochemistry. The cell viability was monitored by MTT assay. Colorimetry method was used to assay the lactate dehydrogenase (LDH) , malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in culture medium. Western blot was used to detect the expressions of endothelial nitric oxide synthase (eNOS) and phosphorylated ERK1/2 in HUVECs.. 11, 12-EET caused minor injury in normal oxygen incubated HUVECs; however, in hypoxia/reoxygenation HUVECs, it raised the cell viability markedly, decreased the LDH release and MDA content, and increased the activity of SOD and the expressions of eNOS and phosphorylated ERK1/2.. 11, 12-EET may prevent against endothelial cell hypoxia/reoxygenation injury. The mechanism may be related to the increased activity of SOD, elimination of oxygen-derived free radicals, and reduction of eNOS and phosphorylated ERK1/2 lesion caused by hypoxia/reoxygenation.

Topics: 8,11,14-Eicosatrienoic Acid; Cell Hypoxia; Cell Survival; Cells, Cultured; Endothelial Cells; Humans; L-Lactate Dehydrogenase; Malondialdehyde; Mitogen-Activated Protein Kinase 3; Nitric Oxide Synthase Type III; Reperfusion Injury; Superoxide Dismutase; Umbilical Veins

Effects of cytochrome P-450 metabolites of arachidonic acid, epoxyeicosatrienoic acids (EETS; 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET), were examined in isolated guinea pig hearts and ventricular myocytes. Addition of 1-16 ng/ml EETs to normal isolated hearts produced no effects on contractility or coronary pressure. In hearts subjected to 60 min of low-flow ischemia, impairment of contractility and declines in heart rate and coronary perfusion pressure were similar in the presence or absence of 1 ng/ml EETs. However, in the presence of either 5,6- or 11,12-EET, recovery was delayed for the first 10 min only. No significant differences were found in any group regarding heart rate, coronary perfusion pressure, or energy metabolite content after 30 min of reperfusion. In myocytes, both 5,6- and 11,12-EET (100 pg/ml, 1.0 ng/ml, and 20 ng/ml) significantly increased cell shortening as well as intracellular calcium concentrations, whereas 8,9- or 14,15-EET was without effect on these parameters. These results describe for the first time the direct effects of various EETs on cardiac cell function as well as their ability to modulate some of the myocardial responses to postischemic reperfusion. The results suggest a potential role for these substances in the response of the heart to pathological insult.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Calcium; Cytochrome P-450 Enzyme System; Dose-Response Relationship, Drug; Guinea Pigs; Heart; Heart Rate; Heart Ventricles; Male; Myocardium; Reperfusion Injury; Time Factors