Abstract
Studies were made on the reason why the absorption of thiamine propyldisulfide (TPD) through the intestinal wall is considerably accelerated as compared with thiamine. The experiment was made with dog's ileum which was separated from the other part and of which the mesenteric vein is cannulated to collect the blood sample. One hour after administration of the sample in the loop of intestine, the content was washed out and the rate of absorption was estimated. It was demonstrated that the large part of the absorbed thiamine was retained in the intestinal wall, while TPD was transferred into the blood. From the experiments with metabolic inhibitors, it was inferred that the absorption of thiamine through the inner surface of intestinal epithelium (first process) is effected by active as well as passive process, and the transport through the cell menbrane into the Lamina propria and blood capillaries (second process) mainly by passive process, while the first process of TPD is mainly effected by passive diffusion, and the second process by active process.
