Erythrocyte membranes definition

Abnormalities in the movement of Li+ across the erythrocyte membrane have been related to psychiatric disorders and also in response to lithium therapy itself. As yet there is relatively little definitive information about the Li+ transport mechanisms operating in therapeutically relevant cell types. 

Only in brush-border membranes of some specialised cells and in erythrocyte membranes there seems to be an Mg-ATPase, which can be stimulated by anions, but only to a minor degree. Moreover, the properties of the enzyme in these membranes differ considerably from those of the activities in the microsomal and mitochondrial fractions of most other tissues. The anion sensitivity of the ATPase activity in the brush-border membranes of placenta and small intestine is a property of the alkaline phosphatase [37,41] and that in erythrocytes is part of the (Ca -b Mg )-ATPase activity [33,34]. Although this does not definitely exclude a role of the enzyme in anion transport, no valid arguments in favour of a role of this enzyme in anion or proton transport have been advanced. 

In one clinical situation, the nature of the autologous carrier may be rather clearly defined this is in drug-induced hemolytic anemia based on immunologic mechanisms. It has been shown that destruction of erythrocytes is due to interaction of IgG antibodies with the red cell membrane after its appreciable penicilloy-lation during therapy with high doeses of penicillin (Levine and Redmond 1967). The antibodies involved were penicilloyl specific but it appeared possible that modified structures of the red cell surface are also contributing to the specificity. If this can be substantiated, the erythrocyte will be definitively implicated as the actual immunogenic carrier. 

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