Relative influence of respiratory and metabolic acid-base changes on renal acid excretion

¹ Veterans Administration Center; and the Departments of Medicine, Physiology, and Obstetrics and Gynecology, University of California Medical Center, Los Angeles, California

Arterial pH of anesthetized dogs was maintained constant for 90 minutes during continuous infusion of 0.15 m HCl or NaHCO₃ (0.3 cc/kg/min.) by adjusting alveolar ventilation with a respiration pump. This resulted in simultaneous metabolic acidosis and respiratory alkalosis (acid infusion) or metabolic alkalosis and respiratory acidosis (base infusion) equal in degree with respect to their effect on blood pH. Since urine pH dropped and renal acid excretion increased during metabolic acidosis and respiratory alkalosis, while pH rose and acid excretion decreased during metabolic alkalosis and respiratory acidosis, metabolic acid-base disturbances appear to exert more influence on renal acid excretion than do respiratory disturbances comparable in terms of their effect on pH. This difference in response was shown not to be due to a time lag in renal response to respiratory disturbances, nor could it be explained by effects on urine flow, renal hemodynamics or renal handling of sodium.

Note:
With the Technical Assistance of Gussie Goldberg and Paul Grubbs