[Beta-glucuronidase activity and morphological alterations in the nervus trigeminus of the rat after application of the neurotropic carcinogen ethylnitrosourea (author's transl)]. / Beta-Glukuronidase-Aktivitáat und morphologische Veränderungen am Nervus trigeminus der Ratte nach Einwirkung des neurotropen Kanzerogens Athylnitrosoharnstoff

Newborn rats were given subcutaneuously 85 mg ethylnitrosourea/kg body weight. The trigeminal nerves of the grown up and of infantile animals were histologically examined and their beta-glucuronidase activity biochemically determined. These activities were compared with those of untreated control animals of the same age. More than 50% of the enzyme values of the experimental animals were significantly higher than those of the controls. Most of the elevated activities were encountered in the central part of the nerve and consisted mainly of the pooled soluble and bound fraction of the enzyme. There is a positive correlation between the level of the enzymatic activity and the degree of morphological changes. An increased enzymatic activity was found in almost 100% of the tumor bearing nerves. Moreover such increased activities were found in a considerable number of histologically tumor free nerves. Ruling out other causes, for instance inflammation, it may be assumed that the increased activity of beta-glucuronidase in the trigeminal nerve of the rat after application of ethylnitrosourea is an expression of its carcinogenic effect and precedes the histologically visible alterations.