Abstract: | The effect of chloroquine (CQ) on phospholipid turnover andde novo synthesis in isolated rat mast cells (IRMC) was studied by determining the incorporation of32P and14C-glycerol into IRMC phospholipids. Incubation of mast cells with chloroquine increased32P incorporation into PI and PS whilst it decreased32P incorporation into PC, PE and PA. In mast cells pretreated with CQ and subsequently stimulated with compound 48/80,32P incorporation into PI, PS and PA fractions was enhanced, while it was decreased into PC and PE, in comparison to 48/80 stimulated IRMC.14C-glycerol incorporation into total IRMC phospholipids was not significantly changed by CQ and compound 48/80 treatment and neither was any dose-dependent effect of CQ on individual phospholipids detected. Our results indicate that chloroquine, similarly to other cationic amphiphilic drugs, may alter membrane PL turnover without changingde novo synthesis of phospholipids. |