scholarly journals Real-Time 2-Photon Imaging of Mitochondrial Function in Perfused Rat Hearts Subjected to Ischemia/Reperfusion

Circulation ◽  
2006 ◽  
Vol 114 (14) ◽  
pp. 1497-1503 ◽  
Author(s):  
Madoka Matsumoto-Ida ◽  
Masaharu Akao ◽  
Toshihiro Takeda ◽  
Masashi Kato ◽  
Toru Kita
Keyword(s):  
Real Time ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Photon Imaging

Abstract 1398: Effects Of Cardioprotective Drugs On Mitochondrial Functions During Myocardial Ischemia/reperfusion Revealed By Real-time Two-photon Imaging Of Perfused Rat Hearts.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Masaharu Akao ◽  
Madoka Matsumoto-Ida ◽  
Masashi Kato ◽  
Moritake Iguchi ◽  
Toshihiro Takeda ◽  
...  
Keyword(s):  
Real Time ◽  
Ischemia Reperfusion ◽  
Laser Scanning Microscopy ◽  
Radical Scavenger ◽  
Two Photon ◽  
Rat Hearts ◽  
Mitochondrial Functions ◽  
Perfused Rat Hearts ◽  
Photon Imaging ◽  
Two Photon Imaging

Background: We recently established a real-time imaging system to monitor the mitochondrial functions in perfused hearts subjected to ischemia/reperfusion, using two-photon laser scanning microscopy. The opening of the mitochondrial permeability transition pore (MPTP), which leads to loss of mitochondrial membrane potential (ΔΨ m ) and mitochondrial dysfunction, is a critical step in cardiomyocyte death during ischemia/reperfusion. We tested the effects of various drugs on Δ Ψ m loss in perfused rat hearts using this novel system. Methods and Results: Langendorff-perfused rat hearts were loaded with a fluorescent indicator of ΔΨ m , tetramethylrhodamine ethyl-ester, and was pretreated with the drugs for 30 minutes. The spatio-temporal changes of ΔΨ m in response to ischemia/reperfusion were monitored at a subcellular level, under excitation with a two-photon laser. Ischemia/reperfusion elicits stereotyped responses in cardiomyocytes; cells maintained a constant ΔΨ m for the cell-to-cell specific period of latency, followed by a rapid and irreversible ΔΨ m depolarization and subsequent cytolysis. The mitochondrial ATP-sensitive potassium channel opener diazoxide (100 μmol/L) and the mitochondrial peripheral benzodiazepine receptor ligand 4′-chlorodiazepam (50 μmol/L) markedly suppressed the latency and thus decreased the likelihood that cells would undergo ΔΨ m depolarization; they not only decreased the number of cells undergoing ΔΨ m loss but also delayed the onset of ΔΨ m loss, whereas it did not change the duration of depolarization in unprotected cells. While this mimicked the effects of ischemic preconditioning to suppress latency, it did not reflect that of cyclosporin A, a MPTP blocker which rather slowed the process of depolarization. In addition, neither a free radical scavenger 2-mercaptopropionyl glycine nor an iron chelator desferroxamine, which reduces the generation of hydroxyl radical through inhibiting the iron-mediated Fenton reaction, was protective. Simply scavenging oxygen radicals or reducing radical generation may not be a feasible strategy to achieve cardioprotection. Conclusions: This novel two-photon imaging provides deeper insight into anti-ischemia/reperfusion therapy targeting mitochondria.

Purinergic Component in the Coronary Vasodilatation to Acetylcholine after Ischemia-Reperfusion in Perfused Rat Hearts

2014 ◽  
Vol 51 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Ángel Luis García-Villalón ◽  
Miriam Granado ◽  
Luis Monge ◽  
Nuria Fernández ◽  
Gonzalo Carreño-Tarragona ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Coronary Vasodilatation ◽  
Perfused Rat Hearts

scholarly journals Cardiac Ischemia and Ischemia/Reperfusion Cause Wide Proteolysis of the Coronary Endothelial Luminal Membrane: Possible Dysfunctions

2011 ◽  
Vol 5 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Blanca Arroyo-Flores ◽  
Erika Chi-Ahumada ◽  
Erika Briones-Cerecero ◽  
Alma Barajas-Espinosa ◽  
Sandra Perez-Aguilar ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Biochemical Changes ◽  
Vascular Endothelial ◽  
Luminal Membrane ◽  
Rat Hearts ◽  
Isoelectric Points ◽  
Perfused Rat Hearts ◽  
Hydrolyzing Enzymes ◽  
2D Gel ◽  
G Protein Coupled

Background: Ischemia and ischemia-reperfusion (I/R) are common clinical insults that disrupt the molecular structure of coronary vascular endothelial luminal membrane (VELM) that result in diverse microvasculature dysfunctions. However, the knowledge of the associated biochemical changes is meager. We hypothesized that ischemia and I/R-induced structural and functional VELM alterations result from biochemical changes. First, these changes need to be described and later the mechanisms behind be identified. Methods: During control conditions, in isolated perfused rat hearts VELM proteins were labeled with biotin. The groups of hearts were: control (C), no flow ischemia (I; 25 min), and I/R (I; 25 min, reperfusion 30 min). The biotinylated luminal endothelial membrane proteins in these three different groups were examined by 2-D electrophoresis and identified. But, it must be kept in mind the proteins were biotin-labeled during control. Results: A comparative analysis of the protein profiles under the 3 conditions following 2D gel electrophoresis showed differences in the molecular weight distribution such that MWC > MWI > MWI/R. Similar analysis for isoelectric points (pHi) showed a shift toward more acidic pHi under ischemic conditions. Of 100 % proteins identified during control 66% and 88% changed their MW-pHi during ischemia and I/R respectively. Among these lost proteins there were 9 proteins identified as adhesins and G-protein coupled receptors. General significance: I and I/R insults alter MW-pHi of most luminal glycocalyx proteins due to the activation of nonspecific hydrolizing mechanisms; suspect metalloproteases and glycanases. This makes necessary the identification of hydrolyzing enzymes reponsible of multiple microvascular dysfunctions in order to maintain the integrity of vascular endothelial membrane. VELM must become a target of future therapeutics.

scholarly journals Moderate exercise prevents impaired Ca2+ handling in heart of CO-exposed rat: implication for sensitivity to ischemia-reperfusion

2010 ◽  
Vol 299 (6) ◽  
pp. H2076-H2081 ◽  
Author(s):  
C. Farah ◽  
G. Meyer ◽  
L. André ◽  
J. Boissière ◽  
S. Gayrard ◽  
...  
Keyword(s):  
Exercise Training ◽  
Antioxidant Status ◽  
Ischemia Reperfusion ◽  
Control Group ◽  
Moderate Exercise ◽  
Plasmic Reticulum ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Exercise Induced ◽  
Moderate Exercise Training

Sustained urban carbon monoxide (CO) exposure exacerbates heart vulnerability to ischemia-reperfusion via deleterious effects on the antioxidant status and Ca2+ homeostasis of cardiomyocytes. The aim of this work was to evaluate whether moderate exercise training prevents these effects. Wistar rats were randomly assigned to a control group and to CO groups, living during 4 wk in simulated urban CO pollution (30–100 parts/million, 12 h/day) with (CO-Ex) or sedentary without exercise (CO-Sed). The exercise procedure began 4 wk before CO exposure and was maintained twice a week in standard filtered air during CO exposure. On one set of rats, myocardial ischemia (30 min) and reperfusion (120 min) were performed on isolated perfused rat hearts. On another set of rats, myocardial antioxidant status and Ca2+ handling were evaluated following environmental exposure. As a result, exercise training prevented CO-induced myocardial phenotypical changes. Indeed, exercise induced myocardial antioxidant status recovery in CO-exposed rats, which is accompanied by a normalization of sarco(endo)plasmic reticulum Ca2+-ATPase 2a expression and then of Ca2+ handling. Importantly, in CO-exposed rats, the normalization of cardiomyocyte phenotype with moderate exercise was associated with a restored sensitivity of the myocardium to ischemia-reperfusion. Indeed, CO-Ex rats presented a lower infarct size and a significant decrease of reperfusion arrhythmias compared with their sedentary counterparts. To conclude, moderate exercise, by preventing CO-induced Ca2+ handling and myocardial antioxidant status alterations, reduces heart vulnerability to ischemia-reperfusion.

scholarly journals Antioxidant Solution in Combination with Angiotensin-(1-7) Provides Myocardial Protection in Langendorff-Perfused Rat Hearts

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Michaela Andrä ◽  
Miriam Russ ◽  
Susanne Jauk ◽  
Mariana Lamacie ◽  
Ingrid Lang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Protection ◽  
Ischemia Reperfusion Injury ◽  
Organ Procurement ◽  
Ischemia Reperfusion ◽  
Morphological Alteration ◽  
Organ Shortage ◽  
Cold Ischemia ◽  
Rat Hearts ◽  
Perfused Rat Hearts

As progressive organ shortage in cardiac transplantation demands extension of donor criteria, effort is needed to optimize graft survival. Reactive oxygen and nitrogen species, generated during organ procurement, transplantation, and reperfusion, contribute to acute and late graft dysfunction. The combined application of diverse substances acting via different molecular pathways appears to be a reasonable approach to face the complex mechanism of ischemia reperfusion injury. Thus, an antioxidant solution containing α-ketoglutaric acid, 5-hydroxymethylfurfural, N-acetyl-L-methionine, and N-acetyl-selenium-L-methionine was combined with endogenous angiotensin-(1-7). Its capacity of myocardial protection was investigated in isolated Langendorff-perfused rat hearts subjected to warm and cold ischemia. The physiological cardiac parameters were assessed throughout the experiments. Effects were evaluated via determination of the oxidative stress parameters malondialdehyde and carbonyl proteins as well as immunohistochemical and ultrastructural tissue analyses. It was shown that a combination of 20% (v/v) antioxidant solution and 220 pM angiotensin-(1-7) led to the best results with a preservation of heart tissue against oxidative stress and morphological alteration. Additionally, immediate cardiac recovery (after warm ischemia) and normal physiological performance (after cold ischemia) were recorded. Overall, the results of this study indicate substantial cardioprotection of the novel combination with promising prospective for future clinical use.

Dose-dependent protection of cardiac function by propofol during ischemia and early reperfusion in rats: effects on 15-F2t-isoprostane formation

2003 ◽  
Vol 81 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Zhengyuan Xia ◽  
David V Godin ◽  
Thomas K.H Chang ◽  
David M Ansley
Keyword(s):  
Antioxidant Capacity ◽  
Functional Recovery ◽  
Ischemia Reperfusion ◽  
Oxidant Injury ◽  
Control Groups ◽  
Early Reperfusion ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Dose Dependent ◽  
Myocardium Ischemia Reperfusion

We examined the effects of propofol (2,6-diisopropylphenol) on functional recovery and 15-F2t-isoprostane generation during ischemia–reperfusion in Langendorff-perfused rat hearts. Before the induction of 40 min of global ischemia, hearts were perfused (10 min) with propofol at 5 (lo-P) or 12 μg/mL (hi-P) in saline or with saline only (control). During ischemia, saline, lo-P, or hi-P was perfused through the aorta at 60 μL/min. During the first 15 min of reperfusion, propofol (5 or 12 μg/mL) was continued, followed by perfusion with 5 μg/mL propofol for 75 min in both propofol-treated groups. After 90 min of reperfusion (Rep-90), heart tissues were harvested for assessment of antioxidant status. In hi-P, we observed increased latency to and greater reduction of ischemic contracture relative to the lo-P or control groups. 15-F2t-Isoprostane concentrations increased during ischemia and were significantly lower in hi-P and lo-P than in control (P < 0.01). At Rep-90, myocardial functional recovery was greater in both propofol-treated groups relative to control, and it correlated positively with tissue antioxidant capacity preservation. Tissue antioxidant capacity was better preserved in hi-P than in lo-P treatment (P < 0.05). We conclude that oxidant injury occurs during ischemia and reperfusion, and propofol provides dose-dependent protection primarily by enhancing tissue antioxidant capacity and reducing lipid peroxidation.Key words: propofol, myocardium, ischemia–reperfusion, 15-F2t-isoprostane.

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