Tracings showing relaxant response to ACh (endothelium-dependent vasodilator) in isolated rat aorta. Benidipine or vehicle was administered orally to rats. Thoracic aortas were isolated at 90 min following benidipine administration. Aortas were cut into rings, and incubated with LPC (5 μmol/L) or ethanol (0.05%) for 60 min. After washing, the rings were pre-contracted using PE (1 μmol/L) and subsequently relaxed using ACh. ACh evoked relaxation in the aortic ring isolated from vehicle-treated rat (A). EDR was markedly attenuated following incubation with LPC (B). LPC-induced attenuation of EDR was inhibited in benidipine-treated rat (C).