Abstract
The rate of utilization of acetoin, butane-2,3-diol, acetate and pyruvate by rabbit-kidney tissue dispersions is greater than in the corresponding kidney "cyclophorase" preparations. Both systems of enzymes can produce acetoacetic acid from acetoin and butane-2,3-diol. The rate of disappearance of acetoin, butane-2,3-diol and pyruvate on incubation at 37[degree] with kidney-tissue dispersions is much greater than can be accounted for by acetoacetate or acetate formation.