The Effect of Thiamine Deficiency in Rats on the Excretion of Pyruvic Acid and Bisulfite- Binding Substances in the Urine*

Thiamine deficiency in all species thus far studied affects the metabolism of pyruvic acid. The lacki until quite recently (l), of a rapid specific method for estimating pyruvic acid necessitated the use of the rapid but less specific technique introduced by Clift and Cook (2). Occasionally it has been estimated by isolation as the 2,4-dinitrophenylhydrazone, by the method of Case (3) or a modification (4) of that method. The Clift and Cook procedure (2) is based on the fact that pyruvic acid (as well as other ketones and aldehydes) combines with bisulfite. Thompson and Johnson (4) were the first to attempt to correlate pyruvic acid with the great increase in bisulfitebinding substances in the blood of thiamine-deficient rats and pigeons. Quantitative measurements in the polyneuritic pigeon of pyruvic acid as the 2,4-dinitrophenylhydrazone demonstrated that the increase in bisulfite-binding substances was due almost entirely to pyruvic acid. Less quantitative estimations of pyruvic acid indicated a similar occurrence in thiamine-deficient rats. Lu (5) measured pyruvic acid and found increased amounts in the blood of thiamine-deficient rats, rabbits, and humans. Sherman and Elvehjem (6) detected no rise in the bisulfitebinding substances of the blood of thiamine-deficient chicks, but they found nearly a 3-fold increase in the case of the cloaca1 ex-