Expression Of Type Ⅰand Ⅲ Collagen In Rat Heart

Background: The normal function of heart was determined not merely by myocardium itself, but the intercellular matrix of the heart. Changes of the intercellular matrix of heart, especially any change of the collagen can lead to severely affected function of the heart. But until now, we do not know the normal age-related changes of collagen in normal conditions of heart; and we still have no clear idea about the methods how they organized and the organizing relationship amongst different types of collagen; and last point, we still can not sure the origin of them.Objective: 1. To investigate the age-related changing situation of type I and type III collagen to see if there was a pattern in. 2. To observe the constructive relationships between type I and type HI collagen. 3. Object to trace the origin of the secretion of collagen in heart. To provide some more morphological basis to further studies on the functional aspects or physiological aspects.Methods: 1. 21 male Wistar rats were divided randomly into infant, young and old groups. Type I and HI collagen expressions of different aged hearts were studied by SP immunohistochemical methods and computer image analysis. 2. The constructive relationships between type I and type III collagen within left ventricle wall of 15 rats' hearts was studied by double-staining Immunohistochemical method and immunohistochemical electron microscopic method. 3. Expression of collagen in the anterior wall of the left ventricle in 10 rats' hearts was studied by the method ofIn-Situ Hybridizational method.Results: 1. Type I and III collagen were all constituted with thick fiber and fibril. The fibril encircled 'every myocardial cell and formed networks with each other. The thick fibers formed plaques, and were located among cardiac muscle groups. The content of type I collagen was more than that of type III. 2. There was distinct expression difference between type I and HI collagen in different aging rat hearts. The collagens distributed densely and evenly in infancy rat heart, and loosely and uniformly in young rat heart, and the contents were increased distinctly with heterogeneous distribution in old rat heart. The cardiac collagen was growing from infant to old rat, and rapid progress of cardiac collagen was during young rat. 3. The content of collagen in right ventricle was more than that of left ventricle of infant rat heart. The collagen of all parts of young and old rat heart are of no difference. 4. Type I and type IE collagen were knitted with each other to form the collagen network but not formed bundles purely with only of kind each. 5. The collagen of heart can be produced in fibroblast, fibrocyte, endothelium and smooth muscle cell of its blood vessels. The latter three produced more.Conclusion: 1. The contents of type I collagen is more than that of type HI collagen, and both of them are increasing with growing. 2. The collagen network of heart was knitted with both type I and type III collagen. 3. The produce and secreting of collagen is of multiple origins. They can be produced by fibroblast, fibrocyte, endothelium and smooth muscle cell.