The role of isoprenoids in vascular smooth muscle: potential benefits of statins unrelated to cholesterol lowering.

Elevated plasma cholesterol is a well recognised risk factor for cardiovascular disease. Numerous studies have shown that a reduction in circulating cholesterol results in a reduced cardiovascular risk. The statins are a group of cholesterol lowering agents which act by inhibition of a key enzyme in cholesterol synthesis; 3-hydroxy 3-methyliglutaryl coenzyme A (HMG CoA) reductase. This enzyme is responsible for the conversion of HMG CoA to mevalonate. In addition to their efficacy as cholesterol lowering agents, statins inhibit the proliferation, migration and signalling of vascular smooth muscle cells. Inhibition of isoprenoid synthesis and resultant reduction in prenylation of key cellular proteins such members of p21ras and p21rho families may underlie some of these effects.