THE EFFECT OF HEXADECYLPHOSPHOCHOLINE ON THE DEGRADATION OF MITOCHONDRIAL PHOSPHOLIPIDS

Hexadecylphosphocholine (HePC) is known as antitumor agent but the mec hanism has not yet been understood. In rat liver mitochondria its effe ct on phospholipid transformation has been studied by quantitative HPT LC and phosphorus determination. From the results it can be concluded that HePC influences the activities of phospholipase A(2), phospholipa se C, phospholipase D, and lysophospholipase A. The phospholipid trans formation as well as the influence of HePC are affected by exogenous c alcium ions. In the presence of calcium HePC has been found to inhibit enzyme activities, whereas in the absence of exogenous calcium ions e nzymatic phospholipid transformations are activated or inhibited depen ding on HePC concentrations.