Cardiac Injury Essay

Most of the cardiac injury ultimately results in development of cardiac fibrosis due to negligible regenerative capacity of heart. Cardiac fibrosis is associated with increased deposition of matrix proteins in the myocardium. The expansion of the cardiac interstitial space in absence of significant cardiomyocyte loss is “reactive interstitial fibrosis” and the formation of scar in response to myocardial infarction is called “reparative fibrosis” [10, 46]. Increased deposition of endomysial and perimysial collagen leads to interstitial fibrosis in fibrotic heart (Figure 5). Increased collagen deposition in adventitia of intramural coronary arterioles is caused by perivascular fibrosis. The initial reactive perivascular fibrosis progressing
Previously rat was used due to its larger size. Increased popularity of mouse models to use in research studies is due to its short gestational period, smaller size, easy to handle, large litter size, low maintenance cost and its extensive characterization of its genome. Also mouse is being used in gene targeted knockouts and transgenic over-expression experiments [50].With various studies it has now been established that the development of heart and vasculature is being regulated by similar genes and signaling pathways in both mice and humans and molecular genetics can play a crucial role in diagnosing and treatment of cardiovascular diseases [51]. Use of mouse as a laboratory animal has advantages of being cheap, smaller size, easy to breed and less criticism regarding animal protection, so larger number of animals can be used (Table-3). Electrocardiography and high resolution echocardiography allows accurate evaluation of heart function, determination of infarct size and post-infarct remodelling characterisation in mouse [52-53]. Also the examination of electrophysiological aspects of heart rhythm and haemodynamic function, the failing or infarcted rodent myocardium in isolated perfused organ (ex vivo) can be done in Langendorff apparatus