Diamide effect on the hypertonic calcium uptake by rat red blood cells.

Red blood cells of rat exhibit an enhanced hypertonic calcium uptake after incubation with diazenedicarboxylic acids bis (N,N-dimethylamide) (diamide). Over the ranges reported in this paper the amount of membrane alteration is strongly and linearly dependent on the diamide concentration and on the osmolarity of the incubation medium. Treatment with 2,3-dihydroxy-1,4-dithiolbutane (dithioerythritol or DTE), after diamide removal, restores red blood cells calcium intake to values similar to those of the control. The results indicate that the sinergic action of diamide and hypertonicity can oxidize some thiol groups essential for the cation barrier maintenance.