The Staining of the Enamel Matrix, and the Substances in the Enamel Organ with Resorcinfuchsin

Abstract

1. When the sections of tooth germ tissues are stained with WEIGERT's resorcinfuchsin, the acid insoluble enamel matrix at the formative stage is stained in the same colour with elastic fibers. And, the various shaping substances stained as well as the enamel matrix, are described in the enamel organ cells at each stage of amelogenesis (Fig. 1).2. The enamel matrix and the above-mentioned substances in the enamel organ cells are singularly stained with resorcinfuchsin, at least, in tooth germ tissues. The other tissue elements of tooth germ are very little stained (Fig. 2).3. For this staining, tooth germ tissues are fixed by ZENKER-formol or 10% formol, decalcified by 3% trichloroacetic acid solution, and are embedded in celloidin. The sections are transferred directly to resorcinfuchsin solution, without staining the nucleus beforehand, are stained for 2-5 days. And then, the nucleuses are stained by hematoxylin or safranin, mounting in balsam.4. Pre-enamel and young enamel are stained most deep by resorcinfuchsin in enamel matrix, especially, young enamel is stained homogeneously. Next, the stainability of the matrix for resorcinfuchsin is lost by degrees as it moves to late transitional enamel through early transitional enamel. The alteration of staining rate of matrix by resorcinfuchsin is paralell to the alteration of colour by hematoxylin-eosin stain or MALLORY's stain (Table 1).5. At the formative stage, the granules stained deep with resorcinfuchsin are observed in infranuclear cytoplasms of ameloblasts of dogs and rats (Fig. 7, 9 and 10), and in infranuclear cytoplasms and intercellular spaces of ameloblasts and in intra- and extracellular portions of stratum intermedium cells, of guinea pigs and rabbits (Fig. 1-6).Simultaneously with the beginning of matrix formation, the mass of substances which is stained slightly amorphously with resorcinfuchsin appears in the portion of ameloblasts which corresponds to GOLGI's zone (Fig. 2, 6, 7 and 9), and goes away in the completion of matrix formation.6. It seems that the granules which are stained deep with resorcinfuchsin, in infranuclear cytoplasms of ameloblasts of various kinds of animals, occur from the slightly stained mass in GOLGI's zone, and transfer to enamel prisms through both TOMES' processes and so-called homogenized TOMES' processes (Fig. 7). It is probable that the mass of slightly stained substances at GOLGI's zone is Golgi's apparatus itself or its products, judging from the portion and duration therein.The so-called homogenized TOMES' processes of dogs and rats are stained with resorcinfuchsin (Fig. 7, 9 and 10).7. It is, most probably, that resorcinfuchsin stainable granules in stratum intermedium are secreted from stratum intermedium cells and transfer to enamel matrix through intercellular spaces of ameloblasts and stratum intermedium cells. It is not a little interesting to find that, in intercellular spaces of ameloblasts, resorcinfuchsin stainable granules are frequently observed near the basal and distal terminal bar apparatus (Fig. 1, and 6). These substances may, anyway, be used for the formation of interprismatic stbstances.8. In order to understand the characteristics of these resorcinfuchsin-stainable substances, various histological and histochemical stainings are employed (Table 2).CHEVREMONT and FREDERIC's test for sulfhydryl group gives positive reactions for enamel matrix, and the transition of reaction rate of matrix is paralell with the transition of staining rate by resorcinfuchsin of it. From this point of view, it is well considered that resorcinfuchsin-stainable substances in enamel matrix will be sulfhydryl group containing potein: keratin or keratin-like substances. It is doubtful, however, whether the granules in enamel organ posess sulfhydryl group or not.