SITES OF ACTION OF CARNITINE AND ITS DERIVATIVES ON THE CARDIOVASCULAR-SYSTEM - INTERACTIONS WITH MEMBRANES

Carnitine plays an essential role in the regulation of long-chain fatt y acid metabolism in skeletal and cardiac muscle, a process that is me diated by well-characterized enzymatic mechanisms. Here, Irving Fritz and Edoardo Arrigoni-Martelli review the evidence that carnitine and i ts O-acyl derivatives also influence membrane fluidity, ion channel fu nctions, smooth muscle contractility, membrane stability and cardiac f unctions. The authors present the view that direct interactions of car nitine derivatives with cell membranes are independent of reactions ca talysed by carnitine acyltransferases. They propose that the novel act ions discussed are implicated in the mechanisms by which carnitine and its derivatives protect perfused hearts subjected to ischaemia or to oxidative stress, and help people suffering from certain types of myoc ardial ischaemia or peripheral arterial disease.