THE CELL MEMBRANE AS A SITE FOR MERCURIAL ACTION 



903 



Hg+''" by erythrocytes or ghosts is very rapid but the situation with chlor- 

 merodrin is different, in that binding to ghosts is rapid but uptake into 

 erythrocytes continues for 2 hr or more; the binding of chlormerodrin is 

 also perhaps more specific for certain SH groups (Rothstein, 1964). Chlor- 



100 



Fig. 7-40. Hemolysis of sheep erythrocytes in a 2% suspension by PM 

 at pH 7.4 and 37°, showing the marked differences over a narrow con- 

 centration range. (From Benesch and Benesch, 1954.) 



merodrin thus might be useful in separating the effects of membrane and 

 internal binding. 



Is hemolysis by the mercurials in any way related to effects on glucose 

 uptake or metabolism? This question cannot be satisfactorily answered 

 since there has been little work where metabolic and hemolytic actions can 

 be compared, and the results available are divergent. The utilization of 

 glucose by human erythrocj'tes is inhibited moderately within a range of 

 Hg++ concentration, the inhibition disappearing as the amount of Hg++ 

 bound is increased (Fig. 7-41) (Weed et al., 1962). In the reversal range, a 

 change in the hemoglobin was observed and some agglutination of the cells 

 occurred. The question arises as to whether the effects on K+ loss and glu- 

 cose utilization result from some action on all the cells or are due to hemol- 

 ysis of a few cells. Weed et al. (1962) assumed that high Hg++ concentra- 

 tions denature the membrane, causing a decrease in permeability, which 

 could explain the reversal of the effect on K+ loss, but is difficult to reconcile 

 with the disappearance of the effect on glucose utilization. It is interesting 

 to compare their results on osmotic fragility with these actions. At the Hg++ 



