The Microfibrillar Component of the Elastic Fibers Morphology and biochemistry

Abstract

Elastic tissue is a fibrous, rubberlike structure composed predominantly of the protein elastin. Mixed or intermediate forms of these arrangements are found in many other tissues. Elastin-associated microfibrils are thus the microfibrillar structures directly associated with amorphous elastic tissue. The elastin-associated microfibrils have an affinity for cationic stains and have been shown to bind lectins and to exhibit specific staining reactions indicative of the presence of glyco-protein material associated with them. Many connective tissues contain fibers which, in the electron microscope, consist of collections of microfibrils, which are morphologically similar to elastin-associated micro-fibrils but which lack an associated amorphous elastic tissue component. The histological staining reactions appear to be in some way related to the microfibrillar components, as microfibril-rich, elastic fibers in developing tissues exhibit oxytalan staining reactions. Microfibrils were first demonstrated in association with elastic fibers in tissue sections of trachea in 1958.