An effect of bicarbonate on the oxidation of pyruvate by kidney homogenates

Abstract

The prepn. and properties of respiring particulate prepns. from homogenized sheep and ox kidney are descr. Kidneys yielded fully active prepns. after storage in frozen 0.9% KCL for 24 hrs. The estimation of acetate by the use of a distillation-diffusion apparatus is descr. Complete oxidation of pyruvate occurred only when bicarbonate (0.0075 [image]) or fumarate (0.00025 [image]) was present and the concn. of pyruvate was below about 0.0025 [image]. Under other conditions the oxidation of pyruvate was incomplete and acetic acid accumulated. Bicarbonate increased the rate of O2 uptake at pH 7.0, 7.4 and 7.6, but not consistently at pH 8.0. The increased O2 uptake was accompanied by a reduction in the accumulation of acetate. Increase of pH from 7.0 to 8.0 had an effect similar to, but smaller than, that of bicarbonate.