A review of myocardial ischaemia/reperfusion injury: Pathophysiology, experimental models, biomarkers, genetics and pharmacological treatment

Cardiovascular diseases are known to be the most fatal diseases worldwide. Ischaemia/reperfusion (I/R) injury is at the centre of the pathology of the most common cardiovascular diseases. According to the World Health Organization estimates, ischaemic heart disease is the leading global cause of death, causing more than 9 million deaths in 2016. After cardiovascular events, thrombolysis, percutaneous transluminal coronary angioplasty or coronary bypass surgery are applied as treatment. However, after restoring coronary blood flow, myocardial I/R injury may occur. It is known that this damage occurs due to many pathophysiological mechanisms, especially increasing reactive oxygen types. Besides causing cardiomyocyte death through multiple mechanisms, it may be an important reason for affecting other cell types such as platelets, fibroblasts, endothelial and smooth muscle cells and immune cells. Also, polymorphonuclear leukocytes are associated with myocardial I/R damage during reperfusion. This damage may be insufficient in patients with co-morbidity, as it is demonstrated that it can be prevented by various endogenous antioxidant systems. In this context, the resulting data suggest that optimal cardioprotection may require a combination of additional or synergistic multi-target treatments. In this review, we discussed the pathophysiology, experimental models, biomarkers, treatment and its relationship with genetics in myocardial I/R injury. SIGNIFICANCE OF THE STUDY: This review summarized current information on myocardial ischaemia/reperfusion injury (pathophysiology, experimental models, biomarkers, genetics and pharmacological therapy) for researchers and reveals guiding data for researchers, especially in the field of cardiovascular system and pharmacology.

Modified Langendorff technique for mouse heart cannulation: Improved heart quality and decreased risk of ischemia

Oscar Langendorff introduced the first method for isolating a heart with contractile activity in 1895. Since then, the Langendorff method has remained a powerful technique in cardiac research and has led to major advances in medicine. The primary goal of the Langendorff method is to provide an isolated heart with oxygen and metabolites via a cannula inserted into the aorta. The Langendorff heart is a complex in vitro technique used primarily in pharmacological and physiological research that allows the evaluation of multiple cardiac hemodynamic parameters including, but not limited to, contractility and heart rate. This article will first provide a brief background of the Langendorff method as well as details regarding organ isolation. Finally, the article will discuss the benefits of a new technique for hanging the isolated heart aorta and the benefits of this technique over traditional methods.

Video Evaluation of the Kinematics and Dynamics of the Beating Cardiac Syncytium: An Alternative to the Langendorff Method

Many important observations and discoveries in heart physiology have been made possible using the isolated heart method of Langendorff. Nevertheless, the Langendorff method has some limitations and disadvantages such as the vulnerability of the excised heart to contusions and injuries, the probability of preconditioning during instrumentation, the possibility of inducing tissue edema, and high oxidative stress, leading to the deterioration of the contractile function. To avoid these drawbacks associated with the use of a whole heart, we alternatively used beating mouse cardiac syncytia cultured in vitro in order to assess possible ergotropic, chronotropic, and inotropic effects of drugs. To achieve this aim, we developed a method based on image processing analysis to evaluate the kinematics and the dynamics of the drug-stimulated beating syncytia starting from the video recording of their contraction movement. In this manner, in comparison with the physiological no-drug condition, we observed progressive positive ergotropic, positive chronotropic, and positive inotropic effects of 10 μM isoproterenol (β-adrenergic agonist) and early positive ergotropic, negative chronotropic, and positive inotropic effects of 10 μM phenylephrine (α-adrenergic agonist), followed by a late phase with negative ergotropic, positive chronotropic, and negative inotropic trends.

Our method permitted a systematic study of in vitro beating syncytia, producing results consistent with previous works. Consequently, it could be used in in vitro studies of beating cardiac patches, as an alternative to Langendorff's heart in biochemical and pharmacological studies, and especially when the Langendorff technique is inapplicable (e.g., in studies about human cardiac syncytium in physiological and pathological conditions, patient-tailored therapeutics, and syncytium models derived from induced pluripotent/embryonic stem cells with genetic mutations).

Furthermore, the method could be helpful in heart tissue engineering and bioartificial heart research to “engineer the heart piece by piece.” In particular, the proposed method could be useful in the identification of a suitable cell source, in the development and testing of “smart” biomaterials, and in the design and use of novel bioreactors and microperfusion systems.

Isolated heart perfusion according to Langendorff---still viable in the new millennium

The isolated perfused mammalian heart preparation was established in 1897 by Oscar Langendorff. The method was developed on the basis of the isolated perfused frog heart established by Elias Cyon at the Carl Ludwig Institute of Physiology in Leipzig, Germany in 1866. Observations made using both methods at the end of the 19th and at the beginning of the 20th century led to important discoveries, forming the basis for our understanding of heart physiology. This included the role of temperature, oxygen and calcium ions for heart contractile function, the origin of cardiac electrical activity in the atrium, the negative chronotropic effect of vagus stimulation and the chemical transmission of impulses in the vagus nerve by acetylcholine. Langendorff himself demonstrated that the heart receives its nutrients and oxygen from blood via the coronary arteries and that cardiac mechanical function is reflected by changes in the coronary circulation. The method underwent many modifications but its general principle remains the same today. Blood, or more commonly crystalloid perfusates, are delivered into the heart through a cannula inserted in the ascending aorta, either at constant pressure or constant flow. Retrograde flow in the aorta closes the leaflets of the aortic valve and as a consequence, the entire perfusate enters the coronary arteries via the ostia at the aortic root. After passing through the coronary circulation the perfusate drains into the right atrium via the coronary sinus. The simplicity of the isolated mammalian heart preparation, the broad spectrum of measurements which can be done using this method, its high reproducibility and relatively low cost make it a very useful tool in modern cardiovascular and pharmacological research, in spite of a few shortcomings. In the last decade the method has brought many important advances in many areas including ischemia-reperfusion injury, cell-based therapy and donor heart preservation for transplant.