Epoxyeicosatrienoic acids (EETs) decrease cardiac ischemia-reperfusion injury; however, the mechanism of their protective effect remains elusive. Here, we investigated the cardioprotective action of a novel EET analog, EET-B, in reperfusion and the role of hypoxia-inducible factor (HIF)-1α in such action of EET-B. Adult male rats were subjected to 30 min of left coronary artery occlusion followed by 2 h of reperfusion. Administration of 14,15-EET (2.5 mg/kg) or EET-B (2.5 mg/kg) 5 min before reperfusion reduced infarct size expressed as a percentage of the area at risk from 64.3 ± 1.3% in control to 42.6 ± 1.9% and 46.0 ± 1.6%, respectively, and their coadministration did not provide any stronger effect. The 14,15-EET antagonist 14,15-epoxyeicosa-5( Z)-enoic acid (2.5 mg/kg) inhibited the infarct size-limiting effect of EET-B (62.5 ± 1.1%). Similarly, the HIF-1α inhibitors 2-methoxyestradiol (2.5 mg/kg) and acriflavine (2 mg/kg) completely abolished the cardioprotective effect of EET-B. In a separate set of experiments, the immunoreactivity of HIF-1α and its degrading enzyme prolyl hydroxylase domain protein 3 (PHD3) were analyzed in the ischemic areas and nonischemic septa. At the end of ischemia, the HIF-1α immunogenic signal markedly increased in the ischemic area compared with the septum (10.31 ± 0.78% vs. 0.34 ± 0.08%). After 20 min and 2 h of reperfusion, HIF-1α immunoreactivity decreased to 2.40 ± 0.48% and 1.85 ± 0.43%, respectively, in the controls. EET-B blunted the decrease of HIF-1α immunoreactivity (7.80 ± 0.69% and 6.44 ± 1.37%, respectively) and significantly reduced PHD3 immunogenic signal in ischemic tissue after reperfusion. In conclusion, EET-B provides an infarct size-limiting effect at reperfusion that is mediated by HIF-1α and downregulation of its degrading enzyme PHD3. NEW & NOTEWORTHY The present study shows that EET-B is an effective agonistic 14,15-epoxyeicosatrienoic acid analog, and its administration before reperfusion markedly reduced myocardial infarction in rats. Most importantly, we demonstrate that increased hypoxia-inducible factor-1α levels play a role in cardioprotection mediated by EET-B in reperfusion likely by mechanisms including downregulation of the hypoxia-inducible factor -1α-degrading enzyme prolyl hydroxylase domain protein 3.

• Klíčová slova
• epoxyeicosatrienoic acid, heart, hypoxia-inducible factor-1α, ischemia-reperfusion, prolyl hydroxylase 3,
• MeSH
• down regulace MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa genetika   metabolismus   MeSH
• funkce levé komory srdeční účinky léků   MeSH
• infarkt myokardu enzymologie   patologie   patofyziologie   prevence a kontrola   MeSH
• kyselina 8,11,14-eikosatrienová analogy a deriváty   farmakologie   terapeutické užití   MeSH
• modely nemocí na zvířatech MeSH
• myokard enzymologie   patologie   MeSH
• potkani Sprague-Dawley MeSH
• prolyl-4-hydroxylasy HIF genetika   metabolismus   MeSH
• proteolýza MeSH
• remodelace komor účinky léků   MeSH
• reperfuzní poškození myokardu enzymologie   patologie   patofyziologie   prevence a kontrola   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• EET-B MeSH Prohlížeč
• Egln3 protein, rat MeSH Prohlížeč
• faktor 1 indukovatelný hypoxií - podjednotka alfa MeSH
• Hif1a protein, rat MeSH Prohlížeč
• kyselina 8,11,14-eikosatrienová MeSH
• prolyl-4-hydroxylasy HIF MeSH

Adaptation to chronic hypoxia represents a potential cardioprotective intervention reducing the extent of acute ischemia/reperfusion (I/R) injury, which is a major cause of death worldwide. The main objective of this study was to investigate the anti-apoptotic Akt/hexokinase 2 (HK2) pathway in hypoxic hearts subjected to I/R insult. Hearts isolated from male Wistar rats exposed either to continuous normobaric hypoxia (CNH; 10% O2) or to room air for 3 weeks were perfused according to Langendorff and subjected to 10 min of no-flow ischemia and 10 min of reperfusion. The hearts were collected either after ischemia or after reperfusion and used for protein analyses and quantitative fluorescence microscopy. The CNH resulted in increased levels of HK1 and HK2 proteins and the total HK activity after ischemia compared to corresponding normoxic group. Similarly, CNH hearts exhibited increased ischemic level of Akt protein phosphorylated on Ser473. The CNH also strengthened the interaction of HK2 with mitochondria and prevented downregulation of mitochondrial creatine kinase after reperfusion. The Bax/Bcl-2 ratio was significantly lower after I/R in CNH hearts than in normoxic ones, suggesting a lower probability of apoptosis. In conclusion, the Akt/HK2 pathway is likely to play a role in the development of a cardioprotective phenotype of CNH by preventing the detachment of HK2 from mitochondria at reperfusion period and decreases the Bax/Bcl-2 ratio during I/R insult, thereby lowering the probability of apoptosis activation in the mitochondrial compartment.

• Klíčová slova
• Heart, Hexokinase, Hypoxia, Ischemia/reperfusion, Mitochondria, Protein kinase B/Akt,
• MeSH
• hexokinasa metabolismus   MeSH
• krysa rodu Rattus MeSH
• myokard enzymologie   patologie   MeSH
• potkani Wistar MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• reperfuzní poškození myokardu enzymologie   patologie   MeSH
• srdeční mitochondrie enzymologie   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hexokinasa MeSH
• protoonkogenní proteiny c-akt MeSH

Continuous normobaric hypoxia (CNH) renders the heart more tolerant to acute ischemia/reperfusion injury. Protein kinase C (PKC) is an important component of the protective signaling pathway, but the contribution of individual PKC isoforms under different hypoxic conditions is poorly understood. The aim of this study was to analyze the expression of PKCepsilon after the adaptation to CNH and to clarify its role in increased cardiac ischemic tolerance with the use of PKCepsilon inhibitory peptide KP-1633. Adult male Wistar rats were exposed to CNH (10 % O(2), 3 weeks) or kept under normoxic conditions. The protein level of PKCepsilon and its phosphorylated form was analyzed by Western blot in homogenate, cytosolic and particulate fractions; the expression of PKCepsilon mRNA was measured by RT-PCR. The effect of KP-1633 on cell viability and lactate dehydrogenase (LDH) release was analyzed after 25-min metabolic inhibition followed by 30-min re-energization in freshly isolated left ventricular myocytes. Adaptation to CNH increased myocardial PKCepsilon at protein and mRNA levels. The application of KP-1633 blunted the hypoxia-induced salutary effects on cell viability and LDH release, while control peptide KP-1723 had no effect. This study indicates that PKCepsilon is involved in the cardioprotective mechanism induced by CNH.

• MeSH
• fyziologická adaptace genetika   MeSH
• hypoxie enzymologie   genetika   patofyziologie   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kardiomyocyty účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• L-laktátdehydrogenasa metabolismus   MeSH
• messenger RNA biosyntéza   genetika   MeSH
• potkani Wistar MeSH
• proteinkinasa C-epsilon antagonisté a inhibitory   biosyntéza   genetika   MeSH
• reperfuzní poškození myokardu enzymologie   genetika   MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibitory proteinkinas MeSH
• L-laktátdehydrogenasa MeSH
• messenger RNA MeSH
• Prkce protein, rat MeSH Prohlížeč
• proteinkinasa C-epsilon MeSH

BACKGROUND: Morphine is often administered to patients for pain management, but it is also recommended to ameliorate some types of cardiovascular diseases. Nevertheless, there is a lack of information regarding the effect of prolonged morphine treatment on myocardial adenylyl cyclase (AC) signaling, which plays an important role in regulating heart function. METHOD: The present work has investigated the consequences of 10-day administration of high morphine doses (10 mg/kg per day) to adult Wistar rats for functioning of the G-protein-mediated AC signaling system. RESULTS: Morphine treatment appreciably affected neither the number of myocardial β-adrenoceptors nor the content of selected subunits of trimeric G-proteins (G(s)α, G(i/o)α, G(z)α, G(q/11)α and Gβ) but the amount of the dominant myocardial AC isoform V/VI almost doubled. These alterations were accompanied by a marked AC supersensitization: the enzyme activity stimulated by manganese, fluoride, forskolin or isoproterenol was considerably increased (by about 50-100%). In contrast, the ability of opioid agonists to inhibit forskolin-stimulated AC activity was slightly but significantly decreased in both groups. Besides that, morphine markedly decreased the incidence of ischemic ventricular arrhythmias induced by coronary artery occlusion, but did not significantly influence infarct size and arrhythmias occurring during reperfusion. CONCLUSION: Overall, these results indicate that prolonged treatment of rats with high doses of morphine substantially alters the function of myocardial G-protein-regulated AC signaling. These alterations are accompanied by a reduced susceptibility to ischemia-induced ventricular arrhythmias.

• MeSH
• adenylátcyklasy metabolismus   MeSH
• antiarytmika aplikace a dávkování   farmakologie   MeSH
• beta-adrenergní receptory metabolismus   MeSH
• buněčná membrána účinky léků   enzymologie   MeSH
• časové faktory MeSH
• krysa rodu Rattus MeSH
• morfin aplikace a dávkování   farmakologie   MeSH
• myokard enzymologie   MeSH
• potkani Wistar MeSH
• proteiny vázající GTP metabolismus   MeSH
• reperfuzní poškození myokardu enzymologie   prevence a kontrola   MeSH
• signální transdukce účinky léků   MeSH
• srdeční arytmie enzymologie   prevence a kontrola   MeSH
• vazba proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenylátcyklasy MeSH
• antiarytmika MeSH
• beta-adrenergní receptory MeSH
• morfin MeSH
• proteiny vázající GTP MeSH

We examined the involvement of phosphatidylinositol 3-kinase (PI3K) and its effector protein kinase B (Akt) in cardioprotective effects of ischemic preconditioning (PC) with particular regards to its role in the protection against ischemia-induced arrhythmias in isolated perfused rat heart. PI3K/Akt inhibitor wortmannin (100 nM) was administered 15 min prior to 30-min regional (left anterior descending coronary artery occlusion) ischemia for the study of ischemic arrhythmias in the hearts perfused at constant coronary flow or prior to 30-min global ischemia followed by 2-h reperfusion for the infarct size (IS) determination (tetrazolium staining) in the hearts perfused at constant pressure. PC procedure (one cycle of ischemia/reperfusion, 5 min each) significantly reduced the total number of ventricular premature complexes (PVC) and severity of arrhythmias (arrhythmia score; AS) over the whole period of left anterior descending coronary artery occlusion in comparison with non-PC controls (PVC 166+/-40; AS 1.6+/-0.2 vs. 550+/-60 and 3.2+/-0.2; respectively; P<0.05). In a setting of global ischemia/reperfusion, PC decreased IS (in % of the left ventricle, LV) by 73 %. Pretreatment with wortmannin modified neither arrhythmogenesis nor IS in the non-PC hearts. Bracketing of PC with wortmannin did not abolish antiarrhythmic protection (PVC 92+/-25; AS 1.7+/-0.2; P<0.05 vs. non-PC hearts). On the other hand, wortmannin increased IS/LV in the PC hearts to 24+/-1.2 % as compared with 9 +/- 0.6 % in the untreated ones (P<0.05). In conclusion, PI3K/Akt inhibition did not affect reduced arrhythmogenesis during ischemia in the PC hearts indicating that in contrast to its positive role in the irreversible myocardial injury, PI3K/Akt activity is not required for protection induced by PC against ischemic arrhythmias in the rat heart.

• MeSH
• androstadieny farmakologie   MeSH
• fosfatidylinositol-3-kinasy metabolismus   MeSH
• infarkt myokardu enzymologie   etiologie   prevence a kontrola   MeSH
• inhibitory fosfoinositid-3-kinasy MeSH
• inhibitory proteinkinas farmakologie   MeSH
• ischemická choroba srdeční komplikace   enzymologie   terapie   MeSH
• ischemické přivykání * MeSH
• krysa rodu Rattus MeSH
• myokard enzymologie   patologie   MeSH
• perfuze MeSH
• potkani Wistar MeSH
• protoonkogenní proteiny c-akt antagonisté a inhibitory   metabolismus   MeSH
• reperfuzní poškození myokardu enzymologie   etiologie   prevence a kontrola   MeSH
• srdeční arytmie enzymologie   etiologie   prevence a kontrola   MeSH
• techniky in vitro MeSH
• wortmannin MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• androstadieny MeSH
• inhibitory fosfoinositid-3-kinasy MeSH
• inhibitory proteinkinas MeSH
• protoonkogenní proteiny c-akt MeSH
• wortmannin MeSH

Reactive oxygen species (ROS) have been implicated in the mechanism of postischemic contractile dysfunction, known as myocardial stunning. In this study, we examined protective effects of antioxidant enzymes, superoxide dismutase (SOD) and catalase, against ischemia/reperfusion-induced cardiac dysfunction and inhibition of Na+,K+-ATPase activity. Isolated Langendorff-perfused rabbit hearts were subjected to 15 min of global normothermic ischemia followed by 10 min reperfusion. The hearts treated with SOD plus catalase did not show significant recovery of left ventricular (LV) end-diastolic pressure compared with untreated ischemic reperfused hearts. Treatment with antioxidants had no protective effects on developed LV pressure or its maximal positive and negative first derivatives (+/-LVdP/dt). Myocardial stunning was accompanied by significant loss in sarcolemmal Na+,K+-ATPase activity and thiol group content. Inhibition of enzyme activity and oxidation of SH groups were not prevented by antioxidant enzymes. These results suggest that administration of SOD and catalase in perfusate do not protect significantly against cardiac dysfunction in stunned rabbit myocardium.

• MeSH
• antioxidancia metabolismus   MeSH
• časové faktory MeSH
• down regulace MeSH
• funkce levé komory srdeční MeSH
• katalasa metabolismus   MeSH
• komorový tlak (srdce) MeSH
• kontrakce myokardu MeSH
• krysa rodu Rattus MeSH
• myokard enzymologie   MeSH
• oxidace-redukce MeSH
• perfuze MeSH
• reperfuzní poškození myokardu enzymologie   patofyziologie   prevence a kontrola   MeSH
• sodíko-draslíková ATPasa metabolismus   MeSH
• sulfhydrylové sloučeniny metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• syndrom omráčeného myokardu enzymologie   patofyziologie   prevence a kontrola   MeSH
• techniky in vitro MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• katalasa MeSH
• sodíko-draslíková ATPasa MeSH
• sulfhydrylové sloučeniny MeSH
• superoxiddismutasa MeSH

The study has been designed to characterize protein systems involved in the responses of rat hearts to chronic doxorubicin (DOX) treatment. We investigated the influence of DOX on cardiac function, mitogen-activated protein kinases (MAPKs) and heat stress proteins (HSPs). Doxorubicin was administered to rats by intraperitoneal injections over a period of 6 weeks. In control and DOX-treated hearts exposed to 20 min global ischemia and 40 min reperfusion the recovery of contractile function after ischemia/reperfusion (I/R) was determined. The levels and phosphorylation state of proteins in tissue samples were analyzed using specific antibodies. We found an activation of extracellular signal-regulated kinases (ERKs) in rat hearts exposed to DOX treatment and better recovery of contractile function after I/R. Analysis of HSPs showed that DOX induced up-regulation of the levels of HSP60 and down-regulation of HSP70 levels. The levels and/or specific phosphorylation of other studied proteins (p38-MAPK, HSP27, HSP90) were not influenced by DOX. The results point to the possible role of ERKs and some HSPs in mechanisms underlying the response of rat hearts to chronic DOX treatment.

• MeSH
• antibiotika antitumorózní MeSH
• chaperon hsp60 metabolismus   MeSH
• doxorubicin MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosforylace MeSH
• kontrakce myokardu MeSH
• krysa rodu Rattus MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• myokard enzymologie   MeSH
• nádorové proteiny metabolismus   MeSH
• nemoci srdce chemicky indukované   enzymologie   patofyziologie   MeSH
• proteiny tepelného šoku HSP27 MeSH
• proteiny tepelného šoku HSP70 metabolismus   MeSH
• proteiny tepelného šoku HSP90 metabolismus   MeSH
• proteiny tepelného šoku metabolismus   MeSH
• reperfuzní poškození myokardu enzymologie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibiotika antitumorózní MeSH
• chaperon hsp60 MeSH
• doxorubicin MeSH
• extracelulárním signálem regulované MAP kinasy MeSH
• Hspb1 protein, rat MeSH Prohlížeč
• mitogenem aktivované proteinkinasy p38 MeSH
• nádorové proteiny MeSH
• proteiny tepelného šoku HSP27 MeSH
• proteiny tepelného šoku HSP70 MeSH
• proteiny tepelného šoku HSP90 MeSH
• proteiny tepelného šoku MeSH

We examined the influence of dietary fatty acid (FA) classes on the expression of protein kinase C (PKC) delta and epsilon in relation to the cardioprotective effects of chronic intermittent hypoxia (CIH). Adult male Wistar rats were fed a nonfat diet enriched with 10% lard (saturated FA [SFA]), fish oil (n-3 polyunsaturated FA [n-3 PUFA]), or corn oil (n-6 PUFA) for 10 weeks. After 4 weeks on the diet, each group was divided into two subgroups that were either exposed to CIH in a barochamber (7000 m, 8 hrs/ day) or kept at normoxia for an additional 5-6 weeks. A FA phospholipid profile and Western blot analysis of PKC were performed in left ventricles. Infarct size was assessed in anesthetized animals subjected to 20-min coronary artery occlusion and 3-hr reperfusion. CIH decreased the n-6/n-3 PUFA ratio in all groups by 23% independently of the initial value set by various diets. The combination of n-3 diet and CIH had a stronger antiarrhythmic effect during reperfusion than the n-3 diet alone; this effect was less pronounced in rats fed the n-6 diet. The normoxic n-6 group exhibited smaller infarctions (by 22%) than the n-3 group. CIH decreased the infarct size in n-3 and SFA groups (by 20% and 23%, respectively) but not in the n-6 group. Unlike PKC epsilon, the abundance of PKC delta in the myocardial particulate fraction was increased by CIH except for the n-6 group. Myocardial infarct size was negatively correlated (r=- 0.79) with the abundance of PKC delta in the particulate fraction. We conclude that lipid diets modify the infarct size-limiting effect of CIH by a mechanism that involves the PKC delta-dependent pathway.

• MeSH
• dietní tuky farmakologie   MeSH
• hypoxie enzymologie   patofyziologie   MeSH
• infarkt myokardu enzymologie   patofyziologie   MeSH
• kardiotonika farmakologie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• kyseliny mastné omega-3 farmakologie   MeSH
• kyseliny mastné omega-6 farmakologie   MeSH
• mastné kyseliny farmakologie   MeSH
• myokard enzymologie   MeSH
• potkani Wistar MeSH
• proteinkinasa C-delta metabolismus   MeSH
• proteinkinasa C-epsilon metabolismus   MeSH
• reperfuzní poškození myokardu enzymologie   patofyziologie   MeSH
• srdeční frekvence účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dietní tuky MeSH
• kardiotonika MeSH
• kyseliny mastné omega-3 MeSH
• kyseliny mastné omega-6 MeSH
• mastné kyseliny MeSH
• proteinkinasa C-delta MeSH
• proteinkinasa C-epsilon MeSH

The transmyocardial turnover of lactate, oxidized and reduced glutathione, malondialdehyde, and the isoenzyme CK-MB before and after restoration of myocardial blood flow was studied in 18 patients undergoing coronary artery surgery. Of this number, ten patients were given oral allopurinol preoperatively; the remaining patients made up the control group. Allopurinol significantly reduced the levels of free oxygen radicals. The enzymatic methods employed did not make it possible to evaluate the protective effect of allopurinol on reperfusion myocardial injury.

• MeSH
• alopurinol aplikace a dávkování   MeSH
• aplikace orální MeSH
• funkce levé komory srdeční účinky léků   MeSH
• glutathion krev   MeSH
• izoenzymy MeSH
• koronární bypass * MeSH
• koronární cirkulace účinky léků   MeSH
• kreatinkinasa krev   MeSH
• kyselina mléčná MeSH
• laktáty krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• malondialdehyd krev   MeSH
• premedikace MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• reperfuzní poškození myokardu farmakoterapie   enzymologie   MeSH
• volné radikály MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• alopurinol MeSH
• glutathion MeSH
• izoenzymy MeSH
• kreatinkinasa MeSH
• kyselina mléčná MeSH
• laktáty MeSH
• malondialdehyd MeSH
• reaktivní formy kyslíku MeSH
• volné radikály MeSH