抄録
In this experimental study, following the cytological study of the transitional epithelium in the normal state (NEMOTO, 1953), the author studied cytologically the absorption of india ink, milk and olive oil transmitted through the epithelium of the urinary bladder and the ureter of the dog. These substances were repeatedly infused into the lumen of the urinary bladder from the ureter of the operated dogs. At 3 hours after the first infusion of the india ink, the fine carbon particules first appear in the supperficial cells (Deckzellen) of the transitional epithelium of both the bladder and the ureter, then in the underlying tall columnar epithelial cells and finally in the basal cells. In these cells the fine cardon particles are deposited in the stainable granules which, as described in the previous paper (NEMOTO, 1953), are the ordinary cytoplasmic inclusions of the transitional epithelium occuring in variable size and number in the GOLGI-field. At 48 honrs after the first infusion the carbon particles are found in the connective tissue of the lamina propria mucosae, where they are partially stored in the histiocytes. In these cells they are also deposited in the vacuoles or the stainable granules. Finally the stainable granules with the deposition of the carbon particles are found in the capillary lumina in the lamina propria.
At 5 or 6 hours after the first infusion of the olive oil or milk, fine particles of the fat deposited in the stainable granules of the cytoplasm occur in the superficial cells of the bladder and the ureter, especially in the cases of the milk infusion, these are found after 20 hours in the underlying columnar epithelial cells and the basal cells.
At 48 hours after the first infusion the fat particles appear in the connective tissue of the lamina propria and are partially stored in the histiocytes; they are like the carbon particles found in the stainable granules. The capillaries in the lamina propria also contain various amounts of the fat granules in their lumina. From the cytological findings mentioned above, the autheor came to the conclusion that the mucous menbrane of the bladder and the ureter possesses the activity to absorb india ink and fat infused into the lumen. The transitional epithelium may play an important role in the absorption process of the mucous membrane. In the second experiment the author injected intravenously india ink, lithion carmine, milk and emulsion of olive oil and liver oil into dogs, guinea pigs and rabbits, and he observed cytologically the mucous membrane of the urinary bladder and the ureter.
In contrast to the infusion of these substances into the lumen, the particles or granules of india ink, carmine and fat were found only in the histiocytes of the lamina propria mucosae of the urinary bladder and the ureter. The effort to detect them in the transitional epithelium proved quite in vain. This fact suggestes that these foreign substances would not be transported through the transitional epithelium when they are administered by way of the blood stream.
