Effects of blood pH changes on potassium excretion in the dog

Abstract

K⁺ excretion rate was measured at normal as well as at rising plasma K⁺ concentration in intact, in K-depleted, and in acetazolamide-treated dogs submitted to acute blood pH changes. The results indicate that, for any given value of glomerular filtration rate, K⁺ excretion rate is determined by at least three factors: 1) plasma K⁺ concentration, 2) blood pH level, and 3) presumably, the H⁺ gradient across the luminal border of the distal tubule. The data further suggest that most of the filtered K⁺ is reabsorbed by the proximal tubule, even in conditions of high filtered loads.