title: The binding of ouabain to normal and chronic lymphocytic leukemic lymphocytes.
abstract: The binding of the cardiac glycoside, ouabain, to cells had been used to quantify the number of active cation pumps. In this study, lymphocytes were incubated with 3H-ouabain and the equilibrium binding analyzed for the maximal number of specific binding sites. Lymphocytes from normal peripheral blood bound 44,200 +/- 9920 molecules/cell, compared with 29,200 +/- 8370 molecules/cell for the lymphocytes of chronic lymphocytic leukemia (CLL) subjects. This difference was significant (p less than 0.01) and did not reflect a lower number of sites on B cells than T cells, since B-cell-enriched lymphocytes from normal peripheral blood showed the same ouabain binding characteristics as the standard T-cell-rich preparation. Although monocytes bind threefold more ouabain than lymphocytes, the small monocyte contamination (3.0%) in normal lymphocyte preparations could not account for the difference between normal and CLL. The fewer ouabain binding sites on CLL lymphocytes may reflect both their smaller size (by 10%) and lower mitotic activity compared with lymphocytes from normal peripheral blood.
mesh_terms: D001402:B-Lymphocytes; D001665:Binding Sites; D006801:Humans; D007945:Leukemia, Lymphoid / Q000097:blood*; D008214:Lymphocytes; D009000:Monocytes; D010042:Ouabain / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D010042:Ouabain