[Changes in the extracellular pH value and its effect on the intracellular pH value of tissues]

The behavior of intracellular pH in different tissues during variation of plasma pH by respiratory and metabolic changes was studied in nephrectomized, unrestrained male Sprague-Dawley rats. The following conclusions can be made: pHi is influenced by respiratory and non-respiratory disturbances of the extracellular acid-base status. pHi is different in different tissues at specified pHe. Skeletal muscle is well protected against slight acidosis because pHi remains constant in a certain range. Our further investigations referred to: Influence of a carbonic anhydrase inhibitor (Diamox) on intracellular tissue pH in vitro and in vivo; Intra-/extracellular tris distribution in tissues at different extracellular pH in vivo; Influence of tris and bicarbonate infusion on intracellular bicarbonate of the whole animal and on intracellular tissue pH in vivo. All these results show that bicarbonate is the more effective substance for correction of metabolic acidosis and should be preferred in clinical practice.