Thiamine Monophosphate, a Normal Constituent of Rat Plasma

Abstract

In plasma of normal rats the presence of thiamine monophosphate, in a completely dialyzable form, was demonstrated by chromatographic procedures. Its content (16.2 ± 0.47 µg/100 ml) accounted for 64% of plasma total thiamine, the rest being free thiamine. Both thiamine compounds of plasma were rapidly and greatly affected by dietary thiamine deficiency. Administration of thiamine or its monophosphate by various routes apparently modified only the free thiamine content. Phosphorylated thiamine (most likely monophosphate) was present in the plasma of all the animal species studied.