[In vitro absorption of vitamin B 6 in various segments of the small intestine in male and female rats].

The influence of different segments of the small intestine on the absorption of vitamin B6 from the mucosal to the serosal solution was studied with varying concentrations of pyridoxine . HCl (PN . HCl) of mucosal solution in 18 male and female rats, each weighing 150 to 160 g. The absorption was measured by the in vitro method with everted sacs, which were prepared of the duodenum (DA 1) and six additional segments (DA 2-7) of a length of 12 cm. The everted sacs were incubated at vitamin B6 concentrations of 0, 0.1, 0.5, 1, 2, 4 microgram PN . HCl per ml mucosal solution. Furthermore the dry matter and protein content of the intestinal wall was analyzed of 44 rats of either sex. Dry matter and protein content of the whole intestine of female rats were 3 per cent higher than of males. On the average of the male and female rats the protein content of the intestinal wall decreased from the proximal to the distal segments of the jejunum significantly by about 6 per cent, whereas dry matter content increased slightly. The ability to absorb vitamin B6 was significantly different between the intestinal segments, parallel in male and female rats. On the average of all concentrations the vitamin B6 uptake into the intestinal all and the vitamin B6 flux into the serosal solution was diminished by 30 and 50 per cent, respectively, from DA 1 to DA 7. A sexuell difference concerning absorbability of vitamin B6 did not appear. Between the concentration of PN . HCl of the mucosal solution and the absorption of vitamin B6 existed a highly positive correlation.