Abstract
Following on the results obtained from the previous study in which the chemical colour reactions for protein and amino acids were employed on the sections of rats' pancreas and the phenol, the imidazol and the indol groups were proved to exist in the zymogen granules of the pancreatic cells, the author, here, has attempted to study the relation of amino acids containing such a group as above described to the production (synthesis) of zymogen granules in the pancreatic cells.
Albino rats of one group were fed for 10 days with the diet which lacks one or all of Tyrosine, Histidine, Tryptophan; the other group were fed for same term with the diet which lacks protein entirely but contains one or all of Tyrosine, Histidine, Tryptophan. Secretory activity of the pancreatic cells, especially the production of zymogen granules in the cells, was observed after administration of the experimental diet, and after the injection of Histamine⋅HCl.
The production of zymogen granules in the pancreatic cells is extremely low after administration of the diet or after the injection of Histamine, when one or all of Tyrosine, Histidine, Tryptophan are lacking in the diet. At times, considerable activity aimed at producing the zymogen granules can be seen in the cell but no production takes place. The feeding of non-protein diet for 10 days causes the functional degeneration of the pancreatic cells. If one of Tyrosine, Histidine or Tryptophan is added into non-protein diet, the functional degeneration is arrested to some extent, and occasionally zymogen granules are produced and increase in the cell after the diet or after the injection of Histamine. But such activity is not verified in all cases of this experiment.
If all three Tyrosine, Histidine and Tryptophan are added into non-protein diet, zymogen granules are produced and are increased in the cell after the diet or after the injection of Histamine, though protein is still entirely lacking.
To sum up these results, it is noted that Tyrosine, Histidine and Tryptophan may be related to the production (synthesis) of zymogen granules in the pancreatic cells, and furthermore they seem to be in the zymogen granules as a component of them, because the phenol, the imidazol and the indol groups have been already proved histochemically to exist in the zymogen granules.
