Abstract: The present invention provides methods for inhibiting smooth muscle cell proliferation, particularly smooth muscle cells present in blood vessel walls. A compound capable of inhibiting blood factor Xa is administered to the smooth muscle cells in an amount effective to inhibit proliferation of the cells. The compound capable of inhibiting blood factor Xa is preferably antistasin or tick anticoagulant peptide (TAP). In other aspects the present invention provides methods for treating atherosclerotic lesions and atherosclerosis, and methods of treating narrowing of the lumen of a blood vessel wherein the narrowing is caused at least in part by hyperplasia of smooth muscle cells in the wall of the blood vessel.

Abstract: Method for treating a patient to inhibit metastasis of malignant cells by administering to the patient a therapeutically effective amount of a composition including a blood anticoagulant and a protease inhibitor. A composition apparently unique for this purpose is a leech salivary gland extract, the anticoagulant effect and protease inhibitory effect of which are believed to be significant. Other significant components may also be present in the leech salivary gland extract and these components may act synergistically in producing the observed antimetastatic effect.