Light and Electron Microscopic Studies on Tissue Mast Cells in the Tongue

Abstract

The present paper describes the distribution, development and histochemical characteristics of the tissue mast cells in mouse tongue. The following results were obtained.1) In the tongue of newborn mice, only a small number of mast cells was apparent while in that of adult mice, a large number of mast cells could be found in loose connective tissue among the lingual muscle bundles.2) All tissue mast cells found in the tongue of newborn mice, exhibited immature cell types which did not stain by the cytochrome c-leucopatent blue method, or indicate metachromasia with azure stains.3) By electron microscopy, the immature mast cells were found to lack microvilli and contained a well-developed granular endoplasmic reticulum and a small number of immature granules in which small progranules and vacuoles could be seen.