PDF herunterladen
Exp Clin Endocrinol Diabetes 1997; 105: 19-21
DOI: 10.1055/s-0029-1211789
© J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

K+-permeability in diabetics and nondiabetics with and without renal insufficiency

G. Kraatz, E. Wolf, S. Gruska
  • Department of Internal Medicine A, University of Greifswald, Germany
Weitere Informationen

Publikationsverlauf

Publikationsdatum:
14. Juli 2009 (online)

Auch verfügbar auf
 als PDF herunterladen  Lizenzen und Reprints

Summary

Looking for causes or consequences of primary hypertension much attention is drawn to the ion transport systems of the cellular membrane. The existence of endogeneous digitalis-like factors, that lower the activity of Na+/K+-ATPase and result in a complex change of electrolyte balance of cells are discussed as a reaction of the organism to salt and volume retention. The measurement of passive permeability of erythrocyte membranes for potassium is an easy and useful method for the detection of disturbances of Na+/K+-transport, especially for extensive screening investigations.

We examined the potassium permeability of erythrocytes in healthy individuals (GR1, n=48), patients with compensated renal insufficiency (GR2, n=36) and diabetics (GR3, n=25) as well as a group of diabetics with renal failure (GR4, n=47). The relative change of potassium concentration in the whole blood, based on the efflux of potassium during a 4-hour-incubation at 37 °C, is defined as a measure for K+-permeability.

K+-concentrations are determined every 60 minutes with ion sensitive electrodes. K+-permeability was significantly increased in patients with compensated renal insufficiency compared to the control group and to diabetics. Diabetics differed markedly in their erythrocyte reaction regarding K+-permeability. Whereas patients with renal insufficiency show an efflux of potassium during investigation there is a decrease of potassium in plasma in diabetics. The K+-permeability results of patients with both diseases are intermediate between the GR2- and GR3 results and are significantly different from the control group. When g-strophanthin is added to inhibit the sodium pump, the differences between the groups are abolished. The decreased K+ permeability in diabetics compared to the control group could be explained by the increased supply of energy-rich substrates for the Na+/K+-ATPase.

Key words

K+-permeability - diabetes mellitus - renal failure