A Synthetic Inhibitor of Factor Xa, DX-9065a, Reduces Proliferation of Vascular Smooth Muscle Cells in Vivo in Rats

• Published in: Thrombosis research Vol. 98; no. 2; pp. 175 - 185
• Main Authors: Kaiser, Brigitte, Paintz, Manfred, Scholz, Olaf, Kunitada, Satoshi, Fareed, Jawed
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 15.04.2000; Elsevier Science
• Subjects: Animals; Anticoagulants - administration & dosage; Anticoagulants - pharmacology; Arteriosclerosis - blood; Arteriosclerosis - etiology; Arteriosclerosis - pathology; Biological and medical sciences; Cardiovascular system; Carotid Artery Injuries - drug therapy; Carotid Artery Injuries - pathology; Carotid Artery, Common - drug effects; Carotid Artery, Common - pathology; Cell Division - drug effects; Disease Models, Animal; DX-9065a; Experimental model; Factor Xa; Factor Xa Inhibitors; Female; Male; Medical sciences; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - injuries; Muscle, Smooth, Vascular - pathology; Naphthalenes - administration & dosage; Naphthalenes - pharmacology; Pharmacology. Drug treatments; Propionates - administration & dosage; Propionates - pharmacology; Rats; Rats, Wistar; Recurrence; Vascular smooth muscle cell proliferation; Vascular wall; BrdU, 5-bromo-2′-deoxyuridine; Vascular smooth muscle cell proliferation; Factor Xa; DX-9065a; PT, prothrombin time; TAP, tick anticoagulant peptide; MAPK, mitogen-activated protein kinases; Experimental model; EPR-1, effector cell protease receptor-1; ANOVA, analysis of variance; TT, thrombin time; PTCA, percutaneous intraluminal coronary angioplasty; VSMC, vascular smooth muscle cells; APTT, activated partial thromboplastin time; Cell proliferation; Serine endopeptidases; Rat; Enzyme; Rodentia; Coagulation Factor Xa; Smooth muscle; Biosynthesis; Experimental study; Artery; Myocyte; Prevention; Peptidases; In vivo; Vertebrata; Chemotherapy; Mammalia; Animal; Hydrolases; Inhibitor; Vascular wall; Atheroma; Coagulation factor
• ISSN: 0049-3848; 1879-2472
• DOI: 10.1016/S0049-3848(99)00213-3

The effect of factor Xa inactivation on the proliferation of vascular smooth muscle cells in vivo was investigated in an experimental restenosis model in rats by using the direct factor Xa inhibitor DX-9065a. In the left common carotid artery, an injury of the vascular endothelium was produced by four external vessel clamps for 60 minutes. After 14 days, 3H-labeled methyl thymidine and 5-bromo-2′-deoxyuridine, respectively, were injected intraperitoneally. After 24 hours, both the left (damaged) and right (nondamaged) carotid arteries were removed, and the incorporation of 3H-methyl thymidine/μg protein was determined. For morphological analysis, the cells were labeled with hematoxylin as well as 5-bromo-2′-deoxyuridine. Stained vascular smooth muscle cell nuclei were counted, and the proliferation index (percentage of 5-bromo-2′-deoxyuridine–positive nuclei to total nuclei stained with hematoxylin) was determined. An external damage of the carotid artery induced proliferation of vascular smooth muscle cells and formation of a neointima within 2 weeks after vessel injury. As compared with control animals, single subcutaneous injection of DX-9065a (2.5, 5, and 10 mg/kg) given 30 minutes before vessel injury significantly reduced the incorporation of 3H-methyl thymidine/μg protein and the total cell number, as well as the proliferation index. The antiproliferative action of DX-9065a was not dose dependent in the range from 2.5 to 10 mg/kg s.c. A combination of bolus injection (5 mg/kg s.c.) with continuous administration (5 mg/kg/d s.c. for 7 and 14 days, respectively) did not increase the antiproliferative effect of DX-9065a. The results indicate a role of factor Xa in the complex pathogenesis of restenosis and the usefulness of a highly effective and selective inhibitor of factor Xa to inhibit proliferative processes.