scholarly journals Diabetic Inhibition of Preconditioning- and Postconditioning-Mediated Myocardial Protection against Ischemia/Reperfusion Injury

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Xia Yin ◽  
Yang Zheng ◽  
Xujie Zhai ◽  
Xin Zhao ◽  
Lu Cai
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Protective Effect ◽  
Myocardial Protection ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Diabetic Patients ◽  
Protective Mechanisms ◽  
Gsk 3Β ◽  
Pathogenic Effects

Ischemic preconditioning (IPC) or postconditioning (Ipost) is proved to efficiently prevent ischemia/reperfusion injuries. Mortality of diabetic patients with acute myocardial infarction was found to be 2–6 folds higher than that of non-diabetic patients with same myocardial infarction, which may be in part due to diabetic inhibition of IPC- and Ipost-mediated protective mechanisms. Both IPC- and Ipost-mediated myocardial protection is predominantly mediated by stimulating PI3K/Akt and associated GSK-3β pathway while diabetes-mediated pathogenic effects are found to be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore, this review briefly introduced the general features of IPC- and Ipost-mediated myocardial protection and the general pathogenic effects of diabetes on the myocardium. We have collected experimental evidence that indicates the diabetic inhibition of IPC- and Ipost-mediated myocardial protection. Increasing evidence implies that diabetic inhibition of IPC- and Ipost-mediated myocardial protection may be mediated by inhibiting PI3K/Akt and associated GSK-3β pathway. Therefore any strategy to activate PI3K/Akt and associated GSK-3β pathway to release the diabetic inhibition of both IPC and Ipost-mediated myocardial protection may provide the protective effect against ischemia/reperfusion injuries.

scholarly journals The Protective Effect of Total Flavones from Rhododendron simsii Planch. on Myocardial Ischemia/Reperfusion Injury and Its Underlying Mechanism

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Sheng-Yong Luo ◽  
Qing-Hua Xu ◽  
Gong Peng ◽  
Zhi-Wu Chen
Keyword(s):  
Myocardial Infarction ◽  
Protective Effect ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Underlying Mechanism ◽  
Assay Method ◽  
Protective Effects ◽  
Rhododendron Simsii ◽  
Rhoa Activity ◽  
Protein Expressions

Objectives. Total flavones from Rhododendron simsii Planch. (TFR) are the effective part extracted from the flowers of Rhododendron simsii Planch. and have obvious protective effects against cerebral ischemic or myocardial injuries in rabbits and rats. However, their mechanism of cardioprotection is still unrevealed. Therefore, the present study was designed to investigate the effect of TFR on myocardial I/R injury and the underlying mechanism. Methods. TFR groups were treated by gavage once a day for 3 days at a dose of 20, 40, and 80 mg/kg, respectively, and then the model of myocardial I/R injury was established. Myocardial infarction, ST-segment elevation, and the expression of UTR, ROCK1, ROCK2, and p-MLC protein in rat myocardium were determined at 90 min after reperfusion. UTR siRNA in vivo transfection and competition binding assay method were used to study the relationship between the protective effect of TFR and UTR. Results. The expression of UTR protein markedly decreased in myocardium of UTR siRNA transfection group rats. TFR could significantly reduce the infarct size and inhibit the increase of RhoA activity and ROCK1, ROCK2, and p-MLC protein expressions both in WT and UTR knockdown rats. The reducing rate of TFR in myocardial infarction area, RhoA activity, and ROCK1, ROCK2, and p-MLC protein expressions in UTR knockdown rats decreased markedly compared with that in WT rats. In addition, TFR had no obvious effect on the increase of ΣST in UTR knockdown rats in comparison with that in model group. In particular, TFR could significantly inhibit the combination of [I125]-hu-II and UTR, and IC50 was 0.854 mg/l. Conclusions. The results indicate that the protective effect of TFR on I/R injury may be correlated with its blocking UTR and the subsequent inhibition of RhoA/ROCK signaling pathway.

scholarly journals The Cardioprotective Actions of Hydrogen Sulfide in Acute Myocardial Infarction and Heart Failure

Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
David J. Polhemus ◽  
John W. Calvert ◽  
Javed Butler ◽  
David J. Lefer
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Acute Myocardial Infarction ◽  
Hydrogen Sulfide ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Multiple Organ ◽  
Organ Systems ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

It has now become universally accepted that hydrogen sulfide (H2S), previously considered only as a lethal toxin, has robust cytoprotective actions in multiple organ systems. The diverse signaling profile of H2S impacts multiple pathways to exert cytoprotective actions in a number of pathological states. This paper will review the recently described cardioprotective actions of hydrogen sulfide in both myocardial ischemia/reperfusion injury and congestive heart failure.

scholarly journals Ischemia/Reperfusion Injury following Acute Myocardial Infarction: A Critical Issue for Clinicians and Forensic Pathologists

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Margherita Neri ◽  
Irene Riezzo ◽  
Natascha Pascale ◽  
Cristoforo Pomara ◽  
Emanuela Turillazzi
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Sudden Death ◽  
Reperfusion Injury ◽  
Nitrosative Stress ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Critical Issue ◽  
Current Standard ◽  
Tissue Alterations

Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality. Reperfusion strategies are the current standard therapy for AMI. However, they may result in paradoxical cardiomyocyte dysfunction, known as ischemic reperfusion injury (IRI). Different forms of IRI are recognized, of which only the first two are reversible: reperfusion-induced arrhythmias, myocardial stunning, microvascular obstruction, and lethal myocardial reperfusion injury. Sudden death is the most common pattern for ischemia-induced lethal ventricular arrhythmias during AMI. The exact mechanisms of IRI are not fully known. Molecular, cellular, and tissue alterations such as cell death, inflammation, neurohumoral activation, and oxidative stress are considered to be of paramount importance in IRI. However, comprehension of the exact pathophysiological mechanisms remains a challenge for clinicians. Furthermore, myocardial IRI is a critical issue also for forensic pathologists since sudden death may occur despite timely reperfusion following AMI, that is one of the most frequently litigated areas of cardiology practice. In this paper we explore the literature regarding the pathophysiology of myocardial IRI, focusing on the possible role of the calpain system, oxidative-nitrosative stress, and matrix metalloproteinases and aiming to foster knowledge of IRI pathophysiology also in terms of medicolegal understanding of sudden deaths following AMI.

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