Regulation of smooth muscle proliferation by heparin in vitro and in vivo.

Smooth muscle cell proliferation is central to the development of atherosclerotic plaques, intimal thickening, and recurrent stenosis in arteries following surgical reconstruction. The factors that might limit this process remain poorly defined. Studies reported recently from several laboratories suggest that heparin administered in pharmacological doses can suppress proliferation of smooth muscle cells. Furthermore, heparin-like molecules are synthesized by vascular wall cells, inhibit smooth muscle growth in vitro, and might act to regulate smooth muscle growth within the arterial wall.