Effect of thiamine deficiency, pyrithiamine and oxythiamine on pyruvate metabolism in rat liver and brain in vivo.

Rats were fed either a thiamine-deficient diet of diets containing pyrithiamine or oxythiamine. When symptoms of thiamine deficiency appeared, the animals were injected intraperitoneally with [2-14C] pyruvate six to twelve minutes prior to sacrifice. Free glutamic and aspartic acids were isolated from liver and brain and degraded. The results indicate that, in thiamine-deficient or oxythiamine-treated rats, pyruvate metabolism in liver and brain is similar to that in normal animals. In contrast, pyrithiamine drastically decreases the oxidative decarboxylation of pyruvate by rat liver.