Citric acid cycle in certain alterations of acid-base balance in human subjects

Abstract

An accurate chromatographic (silica gel) procedure for the quantitative measurement of the stable citric acid cycle acids and certain noncycle acids in urine was developed. The identity of the isolated acids was verified by paper chromatography. The method was applied to a study of urinary excretion of the cycle and other acids during certain alterations in acid-base balance in eight normal subjects, and one diabetic patient. During a “basic” regimen, the “alkaline tide,” and “respiratory alkalosis,” a significant increase in the excretion of citric acid occurred, with no significant change in that of the other cycle and noncycle acids. The “acidic” regimen produced a uniform decrease in the excretion of citrate to values approaching statistical significance; there was no consistent alteration in the excretion of the other acids. A similar decrease in the excretion of citric acid was observed in the patient during diabetic acidosis. It is concluded that of the Krebs cycle and other acids studied, the urinary excretion of only citric acid varies with alterations in acid-base balance. Submitted on February 10, 1961