Histological and Histochemical Observations on the Development Pancreas of Fetal Mouse
1960 Volume 72 Issue 1 Pages 42-58
Details
1960 Volume 72 Issue 1 Pages 42-58
The intracellular distribution of alkaline and acid phosphatases, lipase and RNA in the developing pancreas of fetal mouse was observed histochemically. During the course of this study, general observations on the histogenesis of the pancreas, especially that of the islets of Langerhans, were also carried out. The findings may be summarized as follows:
1. Two successive developmental stages of the islets, the primary and the secondary, were confirmed. No degeneration of the primary islets was however established.
2. The primary islets initially appeared in the dorsal anlage of the pancreas of 10 days as the masses of cells showing an intense basophilia and a high phosphatase activity. The amount of cytoplasmic RNA was rapidly decreased thereafter.
3. The secondary islets appeared in the dorsal anlage of 14 days, while those in the ventral anlage was first observed one or half a day later. The tubular origin of the secondary islets was confirmed, and the primitive cells of this generation of the islets were characterized by an intense activity of alkaline phosphatase. No specific accumulation of RNA in these cells was detected by the staining with pyronin and chrome alum gallocyanin.
4. The activity of acid phosphatase was also fairly restricted to the islets and the duct from the early stage of development, and the activity lasted until the latest date of the intra-uterine life.
5. The activity of lipase was observed only in the fully developed excretory cells having the zymogen granules.
