Abnormal parachloromercuriphenylsulfonate-sensitive cation channel in the erythrocytes of hereditary spherocytosis

The erythrocytes of hereditary spherocytosis (HS) demonstrate an increased inward movement of sodium ions, an alteration which has been proposed as the primary defect leading to cell destruction. Parachloromercuriphenylsulfonate (PCMBS), an agent reacting with sulfhydryl groups of the membrane, increases the cation permeability of normal red cells, but does so to a much lesser extent in the HS red cells. On the other hand, pronase that is specific for amino groups of the membrane increases cation permeability and decreases anion permeability equally in normal and HS red cells. It may be postulated that a decreased number of sulfhydryl sites or a mutation of proteins in the PCMBS-sensitive cation channels of the HS cell membrane result in this hyposensitivity to PCMBS.