The role of active sodium and potassium transport in hyponatremic states in infancy and childhood.
Erythrocytes from 14 infants and children with serum sodium concentrations of 125 mmol/l or less were analyzed for total and Na+, K+-ATPase, sodium and potassium content and ATP concentrations to evaluate the role of active Na+-K+ transport in hyponatremia. In six out of nine patients, with a duration of hyponatremia of more than 48 hours low Na+, K+-ATPase activities and high erythrocyte sodium concentrations and Na+-K+ ratios were found indicating that a decreased Na+, K+-ATPase activity leading to an increased intracellular accumulation of sodium ions may have reduced the extracellular sodium concentration. Three subjects with large sodium losses had high Na+, K+-ATPase activities and normal erythrocyte sodium concentrations. In five cases of hyponatremia with a duration of less than 24 hours the variables indicating active Na+-K+ transport were normal. The therapeutic implications with sodium substitution and the use of drugs affecting active Na+-K+ transport are discussed.
D000251:Adenosine Triphosphatases / Q000097:blood; D000255:Adenosine Triphosphate / Q000097:blood; D000293:Adolescent; D001692:Biological Transport; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000097:blood*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood*
D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases; D011188:Potassium