The Effect of Methotrexate on the Pool of Low-Molecular Weight Sulfur-Containing Compounds in the Brain of Rats

Resumo

Single administration of methotrexate at a dose of 0.1 mg/kg on the first and seventh days is associated with an imbalance in the pool of low-molecular weight sulfur-containing compounds whose severity decreases in the following series: hypothalamus > midbrain > cerebral hemispheres > striatum > cerebellum. In 24 h, homocysteine remethylation in the cerebral hemispheres decreases, transsulfuration activity in the striatum increases, taurine synthesis in the midbrain decreases, homocysteic acid and taurine synthesis in the hypothalamus increases, and, in the cerebellum, the oxidase pathway of cysteine and homocysteine transformation are activated and taurine transsulfuration and biosynthesis is inhibited. At 7 days after a single meth-otrexate administration, the general trend included the inhibition of the oxidation reactions and activation of transsulfuration and decarboxylation in taurine synthesis.