Localization of Annexin V and Agrin in the Intact Sciatic Nerve of Mice

Abstract

Immunohistochemistry methods are widely used in modern microscopic studies. The advantage of immunoelectron microscopy is the possibility of localization of functional proteins in the ultrastructures of the cell. However, different tissues and antigens react differently to the traditionally used fixatives. Selection of optimal conditions for the preparation of immunologically labeled samples for electron microscopic studies is largely based on empirical experience and depends not only on the type of tissue, but also on the purpose of the study. Nervous tissue combines mechanically weak (myelin) and dense (collagen, cell wall) structures, which poses the controversial task of simultaneously ensuring the fixation of the structure of the tissue and the interaction of antibodies with antigen throughout the entire thickness of the sample. This paper presents the method of immunohistochemical labeling, adapted for the study of the localization of annexin V and agrin in the ultrastructure of different parts of the mouse sciatic nerve. Obtained results revealed the preferential localization of both proteins in the myelin sheaths of nerve fibers, which indicates the possible role of these proteins in the functioning of myelin. The density of anti-agrin precipitate in the skin branch is significantly higher than in the tibial, whereas annexin V is more evenly distributed.