Mechanisms of Transcellular Potassium Shifts in Acid-Base Disorders

Abstract

A substantial improvement in our understanding of the determinants of internal potassium balance, the regulation of acidity within body fluids, and the relationship between potassium transport and pH levels has been accomplished in the last forty years [1–4]. Yet, a number of fundamental questions on the linkage between acid-base and potassium transport at the cellular level remain unanswered. I will attempt to summarize our view of this puzzling relationship with the understanding that alternative explanations have been or might be offered at this time. Our analysis of the internal K⁺ exchanges in acid-base disorders will be performed considering the existence of basic determinants of the K⁺-H⁺ relationship as well as modulators of this relationship. The wide range of Δ [K⁺]/Δ pH values in the extracellular fluid observed among the various acid-base disorders [5] may be largely explained by the differential effects of the basic determinants of the K⁺-H⁺ relationship on each disorder. The modulators of the K⁺-H⁺ relationship might either ameliorate or exaggerate the translocation of potassium under a variety of pathophysiological conditions.