[³H]ouabain binding and sodium content in lymphocyte sub-populations and the demonstration of increased binding in type 2 diabetes mellitus

Abstract

The number of specific [³H]ouabain binding sites in T-lymphocytes was determined and linear Scatchard plots were obtained. The number of sites was 30088 ± 3039 (mean ± SD) per lymphocyte in 14 healthy males and 33939 ± 3185 in 11 males with type 2 diabetes (P<0.01). No difference between the dissociation constants were found (K_d = 3.91 and 3.86 mmol/1). The number of binding sites in lymphocytes from 15 healthy males with normal glucose tolerance but with a strong family history of type 2 diabetes did not differ from the controls.

In T-lymphocytes a significantly higher number of specific ouabain binding sites was found than in non-T-lymphocytes (P<0.01). There was no difference between the dissociation constants. (K_d = 3.69 and 3.97 mmol/1).

Intra-lymphocytic sodium was measured in 18 healthy individuals and the mean content was 8.1 ± 2.3 mmol/kg lymphocytes. A lower content of sodium in T- compared to non-T-lymphocytes was also found (5.9 ± 0.8 mmol/kg vs 15.5 ± 0.8 mmol/kg, P<0.001).

There was no correlation between lymphocytes and erythrocytes concerning [3H]ouabain binding sites or sodium concentration.

Key Words:

• cell separation
• diabetes heredity
• electrolytes
• glucose
• glycoside receptors
• insulin
• lymphocyte sub-populations
• Na⁺/K⁺-ATPase