Plasma amino acids are highly dependent on acid-base balance in uremic rats.

Acidosis is a common finding in uremia. We analysed the effect of changes in acid-base balance in 42 Sprague-Dawley rats having longstanding uremia (> 3 mon). The rats were treated with CaCO3 or CaCl2 in a random cross-over trial after being divided into two dietary groups (8% or 18% protein). At the end of each observation period parameters were assessed. The main finding was that plasma amino and keto acid concentrations varied significantly with the acid-base balance and the protein intake. Furthermore a considerable degree of catabolism and anorexia was observed. In addition other confounding variables were observed, e.g. increased corticosterone excretion, electrolyte losses, and proteinuria. Our data underline that plasma amino acid concentrations in uremic rats are highly dependent on acid-base balance and overall protein intake.