Protection of Acid–Base Balance by pH Regulation of Acid Production

Under normal physiologic conditions, acid–base balance is maintained by renal excretion of hydrogen ions generated during the metabolism of dietary protein and other metabolic processes. In normal subjects, these so-called fixed acids are produced at an average rate of approximately 1 mmol per kilogram of body weight, or 50 to 70 mmol per day, with a variety of organic acids accounting for half this amount and sulfuric and phosphoric acids for the remainder. When a disturbance in systemic pH occurs as the result of an excess or loss of acid or base, shifts in body buffers and ventilatory adjustment of . . .