Myocardial susceptibility to ischemic-reperfusion injury in a prediabetic model of dietary-induced obesity

2008 ◽  
Vol 294 (5) ◽  
pp. H2336-H2343 ◽  
Author(s):  
Eugene F. du Toit ◽  
Wayne Smith ◽  
Christo Muller ◽  
Hans Strijdom ◽  
Bernadette Stouthammer ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Infarct Size ◽  
Reperfusion Injury ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Ischemic Reperfusion Injury ◽  
Ischemic Reperfusion ◽  
Percent Recovery ◽  
The Impact

We assessed the myocardial susceptibility to ischemic-reperfusion injury in obese rat hearts in the absence and the presence of predicted circulating concentrations of insulin and fatty acids. Feeding rats a high-calorie diet resulted in increases in body weight, visceral fat content, cardiac hypertrophy, plasma insulin, nonesterified free fatty acid, and triglyceride concentrations. In the absence of both insulin and fatty acids in the coronary perfusate, the hearts of obese rats developed an increased infarct size (41.9 ± 1.9% for obese vs. 22.9 ± 2.3% for control, P < 0.05) and a reduced percent recovery of aortic output (4.2 ± 4.2% for obese vs. 27.7 ± 3.4% for controls, P < 0.05) after coronary artery occlusion and reperfusion. In the presence of insulin in the coronary perfusate, a cardioprotective effect was noted in both groups, an action that was greater in hearts from obese compared with control rats and which abolished the obesity-induced changes in infarct size (13.8 ± 1.2% for controls vs. 21.0 ± 1.6% for obese), and percent recovery of aortic output (60.2 ± 4.7% for controls vs. 45.7 ± 9.4% for obese). Fatty acids (0.7 mM, control; and 1.5 mM, obese) added to the coronary perfusate with in vivo concentrations of insulin dramatically increased infarct size (48.2 ± 3.1% for obese, and 37.5 ± 2.7% for control; P < 0.05 vs. without fatty acids) and decreased percent aortic output recovery (control, 10.4 ± 5.2%, and obese 7.8 ± 3.5%; P < 0.05 vs. without fatty acids) in both groups to similar values. In conclusion, in obesity, the impact of an increased susceptibility of the myocardium to ischemic-reperfusion injury on myocardial injury is likely to be overshadowed by the comparatively greater roles played by predicted increases in circulating insulin and fatty acids found in vivo. These data support the notion that adiposity per se is unlikely to be a valuable predictor of outcomes in ischemic-reperfusion injury.

Abstract 12: EMMPRIN-Targeted Magnetic Nanoparticles for in vivo Visualization and Regression of Acute Myocardial Infarction in a Model of Acute Coronary Artery Occlusion

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Irene Cuadrado ◽  
Maria Jose Garcia Miguel ◽  
Irene Herruzo ◽  
Mari Carmen Turpin ◽  
Ana Martin ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Extracellular Matrix ◽  
Coronary Artery ◽  
Left Ventricle ◽  
Infarct Size ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Gadolinium Enhancement

Extracellular matrix metalloproteinase inducer EMMPRIN, is highly expressed in patients with acute myocardial infarction (AMI), and induces activation of several matrix metalloproteinases (MMPs), including MMP-9 and MMP-13. To prevent Extracellular matrix degradation and cardiac cell death we targeted EMMPRIN with paramagnetic/fluorescent micellar nanoparticles with an EMMPRIN binding peptide AP9 conjugated (NAP9), or an AP9 scramble peptide as a negative control (NAPSC). NAP9 binds to endogenous EMMPRIN as detected by confocal microscopy of cardiac myocytes and macrophages incubated with NAP and NAPSC in vitro, and in vivo in mouse hearts subjected to left anterior descending coronary artery occlusion (IV injection 50mγ/Kg NAP9 or NAP9SC). Administration of NAP9 at the same time or 1 hour after AMI reduced infarct size over a 20% respect to untreated and NAPSC injected mice, recovered left ventricle ejection fraction (LVEF) similar to healthy controls, and reduced EMMPRIN downstream MMP9 expression. In magnetic resonance scans of mouse hearts 2 days after AMI and injected with NAP9, we detected a significant gadolinium enhancement in the left ventricle respect to non-injected mice and to mice injected with NAPSC. Late gadolinium enhancement assays exhibited NAP9-mediated left ventricle signal enhancement as early as 30 minutes after nanoprobe injection, in which a close correlation between the MRI signal enhancement and left ventricle infarct size was detected. Taken together, these results point EMMPRIN targeted nanoprobes as a new tool for the treatment of AMI.

Abstract 90: Diabetes Impairs Post-stroke Cerebrovascular Plasticity And Long-term Functional Recovery.

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Roshini Prakash ◽  
Weiguo Li ◽  
Zhi Qu ◽  
Susan C Fagan ◽  
Adviye Ergul
Keyword(s):  
Cognitive Decline ◽  
Reperfusion Injury ◽  
Functional Recovery ◽  
Diabetic Rats ◽  
Neurological Deficits ◽  
Ischemic Reperfusion Injury ◽  
Post Stroke ◽  
Ischemic Reperfusion ◽  
Sensorimotor Recovery ◽  
The Impact

Background: Stroke associated with pre-existing diabetes worsens ischemic injury and impairs recovery. We have previously shown that type-2-diabetic rats subjected to cerebral ischemic reperfusion injury develop hemorrhagic transformation (HT) and greater neurological deficits. These diabetic rats also exhibit enhanced dysfunctional cerebral neovascularization that increases the risk of bleeding post-stroke. However, our knowledge of vascular and functional plasticity during the recovery phase of diabetic stroke is limited. This study tested the hypothesis that post-stroke neovascularization is impaired in diabetes and this is associated with poor sensorimotor and cognitive outcomes. Methods: Reparative neovascularization was assessed in the lesional and non-lesional areas in diabetic rats after 14 days of ischemic reperfusion injury. 3-dimensional reconstruction of the FITC stained vasculature were obtained by confocal microscopy and stereological parameters including vascular volume and surface area were measured. Astrogliosis was also determined by GFAP staining. The relative rates of sensorimotor recovery, cognitive decline and spontaneous activity were assessed. Results: Diabetes impairs reparative neovascularization in the lesional areas compared to control rats. Astroglial swelling and reactivity was pronounced in diabetic stroke compared to control stroke. Rate of sensorimotor recovery was significantly slower in diabetic stroke compared to the controls. Diabetes also exacerbated anxiety-like symptoms and cognitive decline post-stroke relative to control. Conclusion: Diabetes impairs post-stroke reparative neovascularization and impedes functional recovery. The impact of glycemic control on poor recovery in this critical period needs to be tested. N=6-8 * p≤ 0.05, ** p≤ 0.005

In Vivo Cardioprotection by Pitavastatin From Ischemic-reperfusion Injury Through Suppression of IKK/NF-κB and Upregulation of pAkt–e-NOS

2011 ◽  
Vol 58 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Salma Malik ◽  
Ashok Kumar Sharma ◽  
Saurabh Bharti ◽  
Saroj Nepal ◽  
Jagriti Bhatia ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemic Reperfusion Injury ◽  
Ischemic Reperfusion

scholarly journals Administration of a CO-releasing molecule at the time of reperfusion reduces infarct size in vivo

2004 ◽  
Vol 286 (5) ◽  
pp. H1649-H1653 ◽  
Author(s):  
Yiru Guo ◽  
Adam B. Stein ◽  
Wen-Jian Wu ◽  
Wei Tan ◽  
Xiaoping Zhu ◽  
...  
Keyword(s):  
At Risk ◽  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Effective Means ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Water Soluble ◽  
Arterial Blood

Although carbon monoxide (CO) has traditionally been viewed as a toxic gas, increasing evidence suggests that it plays an important homeostatic and cytoprotective role. Its therapeutic use, however, is limited by the side effects associated with CO inhalation. Recently, transition metal carbonyls have been shown to be a safe and effective means of transporting and releasing CO groups in vivo. The goal of the present study was to test whether a water-soluble CO-releasing molecule, tricarbonylchloro(glycinato) ruthenium (II) (CORM-3), reduces infarct size in vivo when given in a clinically relevant manner, i.e., at the time of reperfusion. Mice were subjected to a 30-min coronary artery occlusion followed by 24 h of reperfusion and were given either CORM-3 (3.54 mg/kg as a 60-min intravenous infusion starting 5 min before reperfusion) or equivalent doses of inactive CORM-3, which does not release CO. CORM-3 had no effect on arterial blood pressure or heart rate. The region at risk did not differ in control and treated mice (44.5 ± 3.5% vs. 36.5 ± 1.6% of the left ventricle, respectively). However, infarct size was significantly smaller in treated mice [25.8 ± 4.9% of the region at risk ( n = 13) vs. 47.7 ± 3.8% ( n = 14), P < 0.05]. CORM-3 did not increase carboxyhemoglobin levels in the blood. These results suggest that a novel class of drugs, CO-releasing molecules, can be useful to limit myocardial ischemia-reperfusion injury in vivo.

scholarly journals Comparative Effects of Verapamil, Nicardipine, and Nitroglycerin on Myocardial Ischemia/Reperfusion Injury

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hitoshi Yui ◽  
Uno Imaizumi ◽  
Hisashi Beppu ◽  
Mitsuhiro Ito ◽  
Munetaka Furuya ◽  
...  
Keyword(s):  
Infarct Size ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Rabbit Model ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Control Group ◽  
Area At Risk ◽  
Group A

The aim of this experiment was to establish whether verapamil, nicardipine, and nitroglycerin have (1) infarct size-limiting effects and (2) antiarrhythmic effects inin vivorabbit hearts during ischemia/reperfusion. Rabbits received regional ischemia by 30 min of left anterior descending coronary artery occlusion followed by 3 hours of reperfusion under ketamine and xylazine anesthesia. The animals were randomly assigned to the following 4 treatment groups: a control group, a verapamil group, a nicardipine group, and a nitroglycerin group. A continuous infusion of verapamil, nicardipine, or nitroglycerin was initiated 5 min prior to ischemia. Infarct size/area at risk decreased in verapamil, and nitroglycerin. The incidence of ischemia-induced arrhythmia decreased in nicardipine, verapamil and nitroglycerin. The incidence of reperfusion-induced arrhythmias decreased in verapamil and nitroglycerin. From the present experimental results, verapamil and nitroglycerin rather than nicardipine did afford significant protection to the heart subjected to ischemia and reperfusion in a rabbit model.

scholarly journals Mechanism of Preconditioning by Isoflurane in Rabbits: A Direct Role for Reactive Oxygen Species

2002 ◽  
Vol 97 (6) ◽  
pp. 1485-1490 ◽  
Author(s):  
Katsuya Tanaka ◽  
Dorothee Weihrauch ◽  
Franz Kehl ◽  
Lynda M. Ludwig ◽  
John F. LaDisa ◽  
...  
Keyword(s):  
Infarct Size ◽  
Superoxide Anion ◽  
Myocardial Infarct ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Myocardial Infarct Size ◽  
Oxygen Species ◽  
Superoxide Anion Production ◽  
Anion Production

Background Reactive oxygen species (ROS) contribute to myocardial protection during ischemic preconditioning, but the role of the ROS in protection against ischemic injury produced by volatile anesthetics has only recently been explored. We tested the hypothesis that ROS mediate isoflurane-induced preconditioning in vivo. Methods Pentobarbital-anesthetized rabbits were instrumented for measurement of hemodynamics and were subjected to a 30 min coronary artery occlusion followed by 3 h reperfusion. Rabbits were randomly assigned to receive vehicle (0.9% saline), or the ROS scavengers N-acetylcysteine (NAC; 150 mg/kg) or N-2-mercaptopropionyl glycine (2-MPG; 1 mg. kg(-1).min(-1)), in the presence or absence of 1.0 minimum alveolar concentration (MAC) isoflurane. Isoflurane was administered for 30 min and then discontinued 15 min before coronary artery occlusion. A fluorescent probe for superoxide anion production (dihydroethidium, 2 mg) was administered in the absence of the volatile anesthetic or 5 min before exposure to isoflurane in 2 additional groups (n = 8). Myocardial infarct size and superoxide anion production were assessed using triphenyltetrazolium staining and confocal fluorescence microscopy, respectively. Results Isoflurane (P &lt; 0.05) decreased infarct size to 24 +/- 4% (mean +/- SEM; n = 10) of the left ventricular area at risk compared with control experiments (43 +/- 3%; n = 8). NAC (43 +/- 3%; n = 7) and 2-MPG (42 +/- 5%; n = 8) abolished this beneficial effect, but had no effect on myocardial infarct size (47 +/- 3%; n = 8 and 46 +/- 3; n = 7, respectively) when administered alone. Isoflurane increased superoxide anion production as compared with control experiments (28 +/- 12 -6 +/- 9 fluorescence units; P &lt; 0.05). Conclusions The results indicate that ROS produced following administration of isoflurane contribute to protection against myocardial infarction in vivo.

scholarly journals Supplemental N-3 Polyunsaturated Fatty Acids Limit A1-Specific Astrocyte Polarization via Attenuating Mitochondrial Dysfunction in Ischemic Stroke in Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jun Cao ◽  
Lijun Dong ◽  
Jialiang Luo ◽  
Fanning Zeng ◽  
Zexuan Hong ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Ischemic Stroke ◽  
Polyunsaturated Fatty Acids ◽  
Mitochondrial Dysfunction ◽  
Artery Occlusion ◽  
Mice Model ◽  
Neuron Death ◽  
The Impact

Ischemic stroke is one of the leading causes of death and disability for adults, which lacks effective treatments. Dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) exerts beneficial effects on ischemic stroke by attenuating neuron death and inflammation induced by microglial activation. However, the impact and mechanism of n-3 PUFAs on astrocyte function during stroke have not yet been well investigated. Our current study found that dietary n-3 PUFAs decreased the infarction volume and improved the neurofunction in the mice model of transient middle cerebral artery occlusion (tMCAO). Notably, n-3 PUFAs reduced the stroke-induced A1 astrocyte polarization both in vivo and in vitro. We have demonstrated that exogenous n-3 PUFAs attenuated mitochondrial oxidative stress and increased the mitophagy of astrocytes in the condition of hypoxia. Furthermore, we provided evidence that treatment with the mitochondrial-derived antioxidant, mito-TEMPO, abrogated the n-3 PUFA-mediated regulation of A1 astrocyte polarization upon hypoxia treatment. Together, this study highlighted that n-3 PUFAs prevent mitochondrial dysfunction, thereby limiting A1-specific astrocyte polarization and subsequently improving the neurological outcomes of mice with ischemic stroke.

scholarly journals Participation of Heart Mitochondria in Myocardial Protection Against Ischemia/Reperfusion Injury: Benefit Effects of Short-Term Adaptation Processes

2015 ◽  
pp. S617-S625 ◽  
Author(s):  
M. FERKO ◽  
I. KANCIROVÁ ◽  
M. JAŠOVÁ ◽  
I. WACZULÍKOVÁ ◽  
S. ČARNICKÁ ◽  
...  
Keyword(s):  
Infarct Size ◽  
Reperfusion Injury ◽  
Membrane Fluidity ◽  
Mitochondrial Membrane ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Favorable Effect ◽  
Ischemic Reperfusion Injury ◽  
Ischemic Reperfusion ◽  
Mitochondrial Membrane Fluidity

Acute streptozotocin diabetes mellitus (DM) as well as remote ischemic preconditioning (RPC) has shown a favorable effect on the postischemic-reperfusion function of the myocardium. Cardioprotective mechanisms offered by these experimental models involve the mitochondria with the changes in functional properties of membrane as the end-effector. The aim was to find out whether separate effects of RPC and DM would stimulate the mechanisms of cardioprotection to a maximal level or whether RPC and DM conditions would cooperate in stimulation of cardioprotection. Experiments were performed on male Wistar rats divided into groups: control, DM, RPC and DM treated by RPC (RPC+DM). RPC protocol of 3 cycles of 5-min hind limb ischemia followed by 5-min reperfusion was used. Ischemic-reperfusion injury was induced by 30-min ischemia followed by 40-min reperfusion of the hearts in Langendorff mode. Mitochondria were isolated by differential centrifugation, infarct size assessed by staining with 1 % 2,3,5-triphenyltetrazolium chloride, mitochondrial membrane fluidity with a fluorescent probe DPH, CoQ9 and CoQ10 with HPLC. Results revealed that RPC as well as DM decreased the infarct size and preserved mitochondrial function by increasing the mitochondrial membrane fluidity. Both used models separately offered a sufficient protection against ischemic-reperfusion injury without an additive effect of their combination.

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