DISTRIBUTION OF VITAMIN A IN TISSUE AS VISUALIZED BY FLUORESCENCE MICROSCOPY

Abstract

An outline of the principles of fluorescence microscopy for visualization of vit. A and a discussion of its instability, the influence of the solvent carrier, and the evidence for the specificity of the fluorescence. The results supplement what can be learned by other methods and also offer a new histologic method for the differentiation of lipids. Vit. A fluorescence is not demonstrable in the epithelium where the first morphologic signs of vit. deficiency appear. Vit. A participates in a known chemical process in the retina from which it does not disappear even in extreme deficiency. The different localizations of vit. A may be due to various factors, among them its participation in chemical processes, its possible destruction as in Kupffer cells, its relation to steroid hormone formation, and its absorption, storage, and transport.