THE CELL MEMBRANE AS A SITE FOR MERCURIAL ACTION 



901 



Minatoya et al. (1960) reported the ED50 for the lytic action on rabbit 

 erythrocytes to be 0.0034 m.M for Hg++ and 0.0174 m.M for mersalyl, and 

 Arbuthnott (1962) found that lysis can occur in 1 hr with 0.017 vnM Hg++ 

 whereas it requires 1 mM p-MB or ethyl-Hg+. The effectiveness depends on 

 the temperature and must also depend on the medium used, since a much 

 less potent action of Hg++ on rabbit erythrocytes was observed by Joyce 

 et al. (1954), lysis occurring in 2 hr with 0.13 mikf. p-MB is much more 

 lytic to rat erythrocytes than is PM, 0.1 vaM of the former lysing almost, 

 completely in 40-60 min, whereas at this time 0.5 mM PM produces only 

 about 50% hemolysis (Moore, 1959), and Hg++ is about 3 times as potent 

 as p-MB, 50% hemolysis being given by 0.4 raM Hg++ and 1.2 mM p-MB 

 (these values estimated from data given) in 90 min (Tsen and Collier, 1960). 

 It is obviously difficult to compare results obtained by different investiga- 

 tors, even when the same species is used, but the definite difference in po- 

 tency between the various mercurials is clear. Although the role of SH 

 groups in erythrocytic membrane structure and function is important, ex- 

 actly how they operate in this capacity is unknown, so it is difficult to 

 speculate on either the mechanisms of hemolysis by the mercurials or the 

 reasons for the differences between the mercurials. Other cells do not lyse 

 so easily in the presence of mercurials, but this does not necessarily prove 

 that SH groups are of more importance for the erythrocytic membrane, 

 since the inherent stability may be less. 



100 



80 



60 



20 



Fig. 7-39. Hemolysis of human erythrocytes by Hg++ at different 



fractional dilution of Tyrode solution {r). The control curve shows the 



hemolysis in the absence of Hg++. (From Jung, 1947.) 



