Uremic acidosis and intracellular buffering.
Skeletal muscle biopsies were performed in 16 controls and 15 non-dialysed end-stage chronic renal failure (CRF) patients presenting untreated metabolic acidosis. Intracellular bicarbonate, pH, water compartments and electrolytes were determined. In 8 of 15 patients muscle ATP and lactate were measured. Intracellular bicarbonate (HCO3i) and pH (pHi) were obtained by means of muscle total carbon dioxide method: a significant (p less than 0.001) reduction in both intracellular acid--base indexes was found in all patients (pHi 6.82 +/- 13 vs. 7.04 +/- 0.05; HCO3i 6.28 +/- 2.07 vs. 11.86 +/- 0.87). Total muscle as well as extracellular water was increased. Muscle sodium and chloride contents were also increased, while no change in potassium and magnesium was detected. A significant decrease of both muscle ATP and lactate was found. The data lead to the conclusion that chronic retention of acids in CRF results in a depletion of the muscle buffer pool and consequently in intracellular acidosis: the latter could be the main cause of the cell energy metabolism derangement described in uremia.
D000138:Acidosis / Q000097:blood*; D000328:Adult; D000368:Aged; D001826:Body Fluids / Q000032:analysis*; D001834:Body Water / Q000032:analysis; D005110:Extracellular Space / Q000032:analysis; D005260:Female; D006801:Humans; D007424:Intracellular Fluid / Q000032:analysis*; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007866:Leg; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism*; D014511:Uremia / Q000097:blood*; D014883:Water-Electrolyte Imbalance / Q000503:physiopathology