[Intestinal absorption of vitamin B6 in vitro in response to the mucosal concentration of pyridoxine . HCl (author's transl)].

The in vitro absorption of vitamin B6 from the mucosal to the serosal solution was studied, using everted sacs of the proximal jejunum of male rats. The concentration and the absorbed amount of vitamin B6 in the intestinal wall and in the serosal solution was measured after an incubation of 45 minutes with 0, 2, 4, 10, 25, 50, 100, 200, 500 micrograms pyridoxine . HCl (PN . HCl) per ml mucosal solution. The concentration and the absorbed amount of vitamin B6, increased linearly with the mucosal concentration of PN . HCl. This could be found for the results of the serosal solution as well as for the results of the intestinal wall, which increased, however, more than those of the serosal solution. The passive diffusion was confirmed as mechanism of the absorption of vitamin B6. Besides, it could be concluded from these results that a homeostatic regulation of vitamin B6 is not due to the mucosal to serosal absorption.