Pactimibe stabilizes atherosclerotic plaque through macrophage acyl-CoA:cholesterol acyltransferase inhibition in WHHL rabbits.

Abstract Novel acyl coenzyme A:cholesterol acyltransferase (ACAT) inhibitor pactimibe was administered as the sulfate salt form to 3-month-old homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits at doses of 0, 10, or 30 mg/kg for 32 weeks. Pactimibe (10 and 30 mg/kg) tended to reduce intimal thickening in thoracic aortic lesions (294 ± 39 and 276 ± 32 μm, respectively, versus 313 ± 37 μm control), histopathological examination revealing significantly increased smooth muscle cell area (12.0 ± 0.9% and 12.3 ± 0.5%, P P Although pactimibe did not alter serum cholesterol levels in WHHL rabbits, it stabilized vulnerable plaque characterized with reduced cholesteryl ester content, enriched collagen fibers and increased smooth muscle cells, indicating potential as a treatment strategy for coronary heart disease.