Inhibition of Rapidly Degraded Membrane Phospholipid by Monensin and CCCP

The aim of this study was to determine the close association between the rapid degradation of newly synthesized membrane phospholipids and secretion that occurs in actively secreting myeloma cells. To achieve this goal, two mechanistically different inhibitors of secretion, monensin and carboxylcyanide m-chlorophenylhydrazone (CCCP), were used. We concluded based on the results of this study that phospholipids reach their site of degradation by active vesicular transport through the golgi apparatus rather than by the extremely rapid, energy independent pathway exhibited by other cells. Evidence that secretion and rapid degradation of membrane phospholipids occur at similar rates and that both are inhibited to similar extends by each of the inhibitors. This suggests that both processes follow identical pathways. These findings demonstrate the active role of some type of dynamic membranes, which serve as an expandable packages for the intracellular transport of secretory product.