The distribution of 5-FU in the gastrointestinal tracts was studied under various conditions of administration in rats.
1) Concerning absorption site of 5-FU in syrup form, it is said the intestinal wall is main route of absorption. By this experiment, it is elucidated that 5-FU is also considerably absorbed through the gastric wall. 2) Adsorption of 5-FU on the gastric wall was strong, and 5-FU remained long in the gastric wall.
3) When 5-FU was administered orally, 5-FU in the gastric wall was higher in concentration and remained longer than in case of intravenous administration.
4) The concentration of 5-FU in the gastric wall was much affected by various conditions of administration. When 5-FU was given at the same dose, the higher the concentration of the drug was, the higher the concentration of 5-FU in the gastric wall was and the longer 5-FU remained.
The concentration of the drug administered influenced more intensively on the concentration of 5-FU in the gastric wall than the fasting did.
5) As the result of delay in 5-FU transfer into plasma by atropine, adsorption of 5-FU on the gastric wall became much stronger and it remained much longer. While, delay in 5-FU transfer into plasma by histamine did not affect on adsorption of 5-FU on the gastric wall.