Encephalotropic Drugs and Cerebral RNA Metabolism

Abstract

Substances which are assumed to influence an impaired memory are also assumed to influence the nucleic acid metabolism of the brain. To investigate this relationship we used pyritinol, which on the basis of experimental and clinical observations is considered to be an encephalotrophic drug. The method we used enables the separation of DNA and four highly purified RNA-fractions. The metabolism of the “rapidly labelled” RNA-, of the rRNA- and of the tRNA-fractions was examined in order to investigate the influence of pyritinol on the rat brain. An oral dosage of 100 mg/kg, administered over several weeks, caused alterations of ³²P-incorporation rate in the single RNA fractions. The ³²P-incorporation of the “rapidly labelled” RNA increased, while the turnover of rRNA decreased. The turnover of tRNA showed no change. To prove the reproducibility of these results and their dependence on dosage and age of animals, we undertook further experiments with 200 and 400 mg/kg pyritinol. For comparison we examined the influence of pentobarbital narcosis and of one other encephalotrophic substance on the RNA metabolism The results of this study and some theoretical implications are discussed.