Effects of Pyrithiamin Injection into the Brain of Rats

Simple dietary thiamin deficiency (8 days) caused a greater decrease (68%) in free thiamin content in the brain than in thiamin phosphates (27%), without bringing about any neurological symptoms of athiaminosis. Injection of 0.03, 0.15 or 0.60 μmole of pyrithiamin into the brains of rats fed a thiamin-deficient diet caused an increase in free thiamin cerebral content in proportion to the dose injected. At the same time, the cerebral content of thiamin phosphates decreased. The oral administration of thiamin for 8 days (0.15 μmole daily) tended to cancel this modification.