[Autoradiographic studies on the distribution of 3H-pyrithioxine in monkey and mouse (author's transl)].

Monkeys and mice received oral and i.p. doses of 3H-labelled pyritinoldihydrochloridemonohydrate (3H-pyrithioxine; Encephabol) and the distribution of radioactivity in the brain and in other organs was investigated by autoradiography. The heaviest label accumulation was present in the pituitary gland. In the monkey the distribution of radioactivity in the brain and in the submandibular gland was different from the distribution found in these organs in the mouse, which may be attributed to the different radioactive metabolites of pyrithioxine produced by the two animal species. Prior to elimination from the body pyrithioxine was completely transformed into metabolites.