Mechanisms of inhibition by heparin of vascular smooth muscle cell proliferation and migration.

Heparin, an inhibitor of vascular smooth muscle cell proliferation and migration, affects a number of other cell functions. These effects include inhibition of growth factor binding, deposition of matrix proteins and gene expression. Various mechanisms have been proposed and, yet, how heparin works as an inhibitor remains unclear. We have postulated that heparin inhibits smooth muscle cell growth and migration by suppressing the expression of matrix-degrading enzymes such as plasminogen activators and interstitial collagenase. The molecular mechanism of heparin's inhibitory action on these proteases is currently under investigation.