Importance of the mitochondrial @entity535 pool in the sensitivity of erythroid cells to @entity2755 : role of @entity2228 and XXXX .

@entity1522 @entity2228 @entity368 @entity535 @entity3793 @entity4588 @entity6007 @entity367 @entity563 @entity1521 @entity1889 @entity2755 @entity4585 @entity369 @entity1446
The @entity535 pool of mitochondria has been recently implicated in the sensitivity of erythroid cells to @entity2755 (CAP) [8]. In the present study, we have analyzed the composition of that pool in the sensitive @entity6007 mitochondria (EM) and compared it with that of the resistant @entity4585 ( @entity4585 ). We have also tested the effect of every major component in each pool on the sensitivity to CAP. The study of endogenous @entity535 composition of EM and @entity4585 was performed with a JEOL 5AH @entity535 analyzer, and the sensitivity to the drug was assayed by determining its interaction with the mitochondrial protein synthesis activity. Analysis of the total endogenous pool showed about 20% more @entity1522 in @entity4585 compared to EM. However, some @entity1522 were present in significantly higher (e.g. @entity2228 , @entity563 and @entity3793 ) or lower (e.g. @entity1521 , @entity368 , @entity369 , @entity367 and @entity1889 ) quantity within EM. When compensating for each low @entity535 in either @entity4585 or EM by addition of that particular acid to the incubation medium, only @entity2228 and @entity563 had a significant effect. Thus, the addition of @entity2228 or @entity563 enhanced the sensitivity to CAP from 14 to 49-52% in @entity4585 , but were without effect in EM. Addition of the other acids to either mitochondria gave little or no effect. Since @entity563 could be interconvertible intramitochondrially to @entity2228 , and because the latter with @entity4588 are the first reactants in heme biosynthesis which is initiated inside the mitochondria, it would appear that erythroid cell sensitivity to CAP is predetermined by the mitochondrial @entity2228 - @entity563 pool and might be somehow related to the pathway of @entity1446 biosynthesis in these cells.
