Abstract
According to the FUJIE's experimental results demonstrating an anti-histamic action of human parotid saliva both in vitro and in vivo, saliva in the OGATA's internal secretion theory of salivary gland will be related with a histamine regulator in the blood. Here the author investigated morphologically the secretory function of the parotid gland cells after the artificial increase of histamine in the blood. Histamine hydrochloride was injected subcutaneously into rats 3mg daily, and the animals were classified into 5 groups being injected 1, 15, 30, 45 and 60 times respectively. Materials were taken on the next day after the last injection, before and after the diet administration.
Results obtained can be summarized as follows. With a repeating the injection the secretion vacuoles are always accumulated in the cells, the gland lumen dilates positively and the weakly stained content can be recognized not only in the gland lumen but also in the intercalated portion and the striated duct. These demonstrate the functional performance of an increased discharge and a still more increased production in the cells, regardless of the diet administration. On the other hand, the cell-nuclei increase their size, and the nuclear contents, RNA and DNA, increase often over their size-augmentation. According to the investigations by K. FUJIE and T. SHIRAYAMA on the relation between the size and content, especially RNA and DNA, of the nucleus and the cell function of the parotid gland, the present author's findings on the cell nucleus confirm an active production and discharge of the secretory substance of the cells, and the observations obtained from the secretion vacuoles in the cells, from the gland lumen and from the secretory duct coincide with those obtained from the cell nucleus. Perhaps it becomes an important support for the theory which assert the absorption of saliva into the blood and the regulative action of the saliva on histamine in the blood, because the anti-histamic action of the parotid saliva (FUJIE) and the remarkable increase of histamine in the blood after an extirpation of the parotid glands (NAKAO) have been previously demonstrated.
