Effects of hypothyroidism and thyroxine substitution on the metabolism of L-methionine, L-cystathionine and taurine in developing rat brain.

In hypothyroidism induced by radioiodine the activity of cystathionine synthase and the concentration of L-cytathionine in cerebrum and cerebellum of developing rat decreased markedly. The amount of taurine was significantly higher in cerebral and cerebellar tissue of hypothyroid rats than in corresponding parts of normal rat brain. Early substitution therapy with L-thyroxine corrected these changes.