Histochemical Studies on the Gland Cells

Abstract

The phenol group in the apical region of the cytoplasm and the imidazol group in the secretory granules in the gastric chief cells have been proved to exist by histochemical studies. Spots similar to histidine, tyrosine, leucine and methionine have been obtained from the extract of the superficial tissue of the gastric mucosa in which the gastric hormone productin - it is secreted from the gastric surface epithelial cells and promotes the production of secretory granules in the gastric chief cells - may be contained. Using these findings, the author has studied the effect of these substance on the secretory activity of the gastric chief cells. For this purpose, the animals were fed for 10 days, 1. with the diet lacking one or all of these substances, and 2. with the non-protein diet with one or all of these substances added. Then the gastric chief cells were observed.In case of the feeding with the diet lacking one or both of Tyrosine (the phenol group) and Histidine (the imidazol group), the production of secretory granules in the chief cells is extremely curtailed and no increase of the granules in the cell can be seen after administration of the diet. The productin vacuoles in the surface epithelial cells are few and show no fluctuation after the diet. If histamine⋅HCl was injected, the production of secretory granules seems to be activated in the cell but no increase of the granules in the cell is seen. That is, the lack of Tyrosine and Histidine brings about 1. an inhibitive effect of the production of the factor which promotes the production-activity of secretory granules in the chief cells, and 2. an arrest of the synthesis of secretory granules in the chief cells. The lack of Leucine or Methionine produces no effect such as these. In other words, Leucine and Methionine seem to have no connection with the secretory activity of the gastric chief cells.The feeding with non-protein diet for 10 days causes the functional degeneration of the gastric chief cells. The addition of Tyrosine or Histidine to the diet is effective in reducing functional degeneration. The addition of Histidine especially, can cause the gastric chief cells to synthesize the secretory granules to some extent. When Tyrosine and Histidine are added into non-protein diet, the functional activity of the chief cells is almost similar to that of the normal case, and an obvious increase of the secretory granules in the cell, together with a gradual vacuolization of them can be observed after administration of the diet. The fluctuation of the productin vacuoles in the surface epithelial cells seems also to be identical with that of the normal case.As a result of these observations, it will be noticed that Tyrosine and Histidine are essential for the synthesis (production) of secretory granules in the gastric chief cells and thus the significance of the phenol group and the imidazol group which are proved to exist in the chief cells by the histochemical methods becomes intelligible. It will also be noticed that these amino acids are also related to the factor which activates the production of secretory granules of the gastric chief cells.