Rats were fed with experimental artificial diet which contained constant quantity of fat, different quantities of protein and carbohydrate as represented in table 1, then the secretory function of the pancreatic cells were observed morphologically.
In the feeding with non-protein diet (0% protein and more than 80% carbohydrate), the cell function was extremely low, and it was demonstrated that the secretory function of the pancreatic cells for carbohydrate-digestion might be slight. In the prolonged feeding many degenerated cells appeared, which might be owing to a lack of protein, not to a functional degeneration. In the feeding with high protein diet (80% protein and less than 10% carbohydrate) the cell function was extremely vigorous and continued for a long time after the administration. In the prolonged feeding the degeneration could be seen in many cells, which might be owing to the functional overwork. In the other feeding with 20%, 40% or 60% protein diet, the secretory function of the pancreatic cells became more vigorous and more continuous according to an increment of the protein content. These characteristics of the cell function, especially the dietetic characteristics in the production of the zymogen granules in the cells are explainable with the superior or inferior secretion of productin at each time, which can be presumed from the fluctuation of productin vacuoles in the gastric surface cells. It was concluded that the dietetic characteristics in the production of zymogen granules must be attendant to the characteristic secretion of productin due to the diet content.
The discharge of zymogen granules was almost concomitant with the production-performance. Therefore it was also characteristic in each case. The author compared this with the results of other investigators and reached the conclusion that the characteristic secretion owing to the diet content could be also applicable to the secretin secretion (BAYLISS and STARLING) as well as to the productin secretion.