[The influence of prednisolut on the induction of neurogenic tumours in rats by N-methyl-N-nitrosourea (author's transl)].

Repeated intraperitoneal injections of methylnitrosourea (MNU, 10 mg/kg b. w.) lead to tumours of the nervous system in 32 out of 44 hooded rats (72.7 per cent) and to extraneural growths in 38 animals (86.4 per cent). After combined application of MNU and intramuskular injections of prednisolute (0.56 mg/kg b. w.), in 11 out of 42 rats (26.2 per cent) tumours of the nervous system were found. In this group, there were extraneural tumours in 17 animals (40.5 per cent). The results were compared with findings of other authors obtained after combined application of chemical carcinogens and corticosteroid hormones.