Effects of hydroxythiamine and citrate on several reactions of the pentose phosphate cycle and glycolysis]

Hydroxythiamin was shown to inhibite distinctly phosphofructokinase and phosphohexoisomerase besides a direct antivitaminous effect on transketolase. In this case the regulatory action is likely to be carried out by erythrose-4-phosphate, accumulating in liver tissue. Citrate (administered separately and together with hydroxythiamin) is assumed to influence indirectly the transketolase activity affecting the total regulation of carbohydrate metabolism.