Red blood cell electrolyte changes in patients with juvenile diabetes mellitus.

The sodium and potassium concentrations of the red blood cells and the serum were investigated in 21 children with diabetes mellitus. Measurements were made prior to and 1 and 2 hours following insulin administration. Before insulin treatment, the sodium level in the red blood cells of the diabetes patients was significantly higher that the control level, while the potassium level was significantly depressed. These differences were not observed 1 and 2 hours following insulin administration. Attention is drawn to the rapid and extensive electrolyte changes in the red blood cells of diabetics in response to insulin. The potassium content of the serum of the diabetics was significantly decreased by insulin administration. No correlation was found between the electrolyte levels and the fasting blood glucose levels. A weak negative correlation (p less than 0.02) was observed between the potassium content of the red blood cells and the duration of the illness. The pathogenetic, diagnostic and therapeutic implications of the results are discussed.

[Isotope study of in vitro K(+) uptake and release of erythrocytes in juvenile diabetes with 86Rb]. / Isotopische Untersuchung der in vitro-K(+)-Aufnahme und -Abgabe der Erythrozyten beim juvenilen Diabetes mit 86Rb.

In order to determine the reasons for a previously observed elevated intracellular Na+ and a decreased K+ level, the K+ uptake and release of the red blood cells in type I diabetics were examined with 86Rb. The K+ release and the ouabain-insensitive K+ uptake were different from those in the controls. Under the present experimental conditions, there was no decrease in ouabain-sensitive K+ uptake indicative of the activity of K+, Na(+)-ATPase. Likewise, an elevated activity normalizing a lower K+ level could not be detected. Further, there were no significant differences in the reaction kinetic parameters: KM[diab.]:4.21 +/- 1.38 mM/l, KM[contr.]:4.14 +/- 0.99 mM/l Vmax[diab.]:2259 +/- 326 nmol/ml red blood cell/hour Vmax[contr.]:2354 +/- 462 nmol/ml red blood cell/hour. These alterations are regarded as partial phenomena of the complex membrane function disturbances in diabetic red blood cells.

Sodium and potassium concentrations in red blood cells and plasma in children with congenital heart defect.

The sodium and potassium concentrations of the red blood cells and plasma were investigated in 93 children with cardiac disease, most of them with congenital heart defect, and in 48 healthy children of the same age. The red blood cell sodium and potassium concentrations were constant within a narrow range in normal subjects, but varied profoundly in pathological conditions. Digitalis treatment caused RBC Na+ and plasma K+ levels to increase and the RBC K+ level to decrease by blocking the Na+-K+ pump. The highest RBC Na+ concentration was observed in critically ill patients with congestive heart failure treated with digoxin. An augmented RBC sodium value was found in heart malformations with left to right shunt and in congestive cardiomyopathy that was not treated, whereas in patients with right to left shunt lower RBC sodium, higher RBC potassium and plasma potassium values were registered without any treatment. In cases of hyperkinetic circulation without any congenital heart defect the value of RBC sodium was definitely low. A low sodium and a high potassium level of the RBC were found after total correcting heart surgery. It is concluded that measurement of changes in sodium and potassium concentrations of the red blood cells is not a reliable method for assessment of the efficacy of digitalis treatment. The results point to the accompanying phenomena at a cellular level in heart disease.

Sodium and potassium concentrations of red blood cells and plasma in children with nephrotic syndrome, uraemia and pyelonephritis.

The sodium and potassium concentrations of the red blood cells and the plasma in 38 children with pyelonephritis (19 acute, 10 chronic and 9 healed), 5 children with uraemia, and 20 children with nephrotic syndrome were compared with those of control children. The red blood cell sodium concentration was lower in patients with acute pyelonephritis, uraemia, and steroid-treated nephrotic syndrome, and higher in those with chronic pyelonephritis and nephrotic syndrome not treated with steroids. Except in uraemic cases, these alterations were not accompanied by plasma sodium and potassium changes. The results might be explained by pathological Na+ and K+ transport processes in the red cell membrane. The possible role of extracellular fluid volume changes, sodium loss and water retention are discussed.