Erythrocyte Ouabain Binding Capacity as a Possible Cellular Index of Hyperthyroid Status

Abstract

The maxium ouabain binding capacity in erythrocytes from 8 normal subjects and 14 patients with hyperthyroidism was assessed by measuring [³H]-ouabain binding. The mean value for maximum ouabain binding capacity was significantly lower in the patients than in normals (0.422±0.084 vs 0.671±0.095 pmol per 10⁹ cells, p<0.001). Furthermore, a close inverse correlation was found between the ouabain binding capacity and serum T₃ (r=-0.766; p<0.01) or T₄ (r=-0.870; p<0.001) levels. These results suggest that the maximum ouabain binding capacity in erythrocytes may provide a useful index of the peripheral effect of thyroid hormone.