Azelnidipine has anti-atherosclerotic effects independent of its blood pressure-lowering actions in monkeys and mice

Calcium channel blockers (CCBs) have been shown to improve clinical outcomes in atherosclerotic vascular disease. The mechanisms underlying the vasculoprotective effects of a third-generation calcium channel blocker, azelnidipine, are incompletely understood. We asked whether azelnidipine attenuates atherosclerosis in monkeys and mice beyond its blood pressure-lowering effects. Cynomolgus monkeys were randomized to three groups after 4 weeks of a high cholesterol diet: control group (no treatment) and 3 and 10 mg/kg daily azelnidipine; these doses have no effect on systemic arterial pressure or heart rate. Atherosclerosis was induced in the aorta by balloon injury, and the diet and treatment were continued for an additional 24 weeks. Azelnidipine did not affect blood lipid profiles, but reduced the development of atherosclerosis as detected by the elimination of local oxidative stress and reduced expression of monocyte chemoattractant protein-1 and platelet-derived growth factor. Azelnidipine also reduced the proliferation and migration of vascular smooth muscle cells in vitro. In atherosclerotic ApoE-knockout (ApoE-KO) mice fed a high cholesterol diet, azelnidipine but not amlodipine reduced the development of atherosclerosis. Neither drug changed the lipid profiles or systolic blood pressure of the mice. Thus, azelnidipine at clinically relevant doses exhibited anti-atherosclerotic effects in monkeys and mice independent of its blood pressure-lowering effects, suggesting that azelnidipine might be as a "vasculoprotective calcium channel blocker". (C) 2007 Elsevier Ireland Ltd. All rights reserved.