[Histochemical and ultrastructural investigations on the activity of methylglyoxal (bis)-guanylhydrozan (methyl-GAG) on organ cultures of malignant tumors (author's transl)].

Methyl-GAG was tested in organotypic cultures of malignant tumors of human and mice. In 3 cases, a reduction of the activity of two oxydoreductases (lactate dehydrogenase and NADH-diaphorase) after treatment with methyl-GAG was observed whereas in 19 other cultivated tumors no change of enzyme activity was induced by methyl-GAG. Electronmicroscopy revealed only minor structural alterations of tumor cells after application of methyl-GAG as compared with control cultures.