The Internal Distribution of Hydrogen Ions With Varying Degrees of Metabolic Acidosis1

Abstract

Hydrochloric acid was administered intravenously to dogs in order to define the internal distribution of administered hydrogen ions with varying degrees of metabolic acidosis. Experiments in which acid was infused continuously appeared to indicate preferential utilization of extracellular buffers in the initial phase with the contribution of intracellular buffers becoming more important as the acidosis increased in severity. However, when the acid load was administered intermittently, allowing time for equilibrium to occur, the partition of hydrogen ions between extracellular and intracellular buffers was essentially unaffected by the degree of acidosis. At equilibrium the percentage reduction in plasma bicarbonate concentration provided an approximate index of the percentage reduction in total body buffer stores.