Preventing Effect of Diltiazem on the Damage of Cultured Aortic Smooth Muscle Cells Induced by Hyperlipidemic Serum
Sadatoshi Birou, Kazuto Saito, Hideaki Fukunaga, Hiromitsu Tanaka · The Journal of Japan Atherosclerosis Society · 1986
To clarify the mechanism of protection from atherosclerosis by calcium antagonist, we examined the effect of diltiazem on damages of cultured aortic smooth muscle cells (CASM) induced by hyperlipidemic serum (HLS). CASM were prepared according to the modified method of Chamley et al. After 7 days of cultivation, the concentration of the medium containing FBS was reduced gradually to stop the proliferation. Then the medium was replaced with the medium containing HLS or HLS and diltiazem (1μg/ml). HLS showed injurious action on the CASM. The trypan blue positive cells (dead cells) were 14±3% in control, 22±2% in HLS and 15±4% in HLS plus diltiazem. The 51Cr-%release was 10±1% in control, 16±1% in HLS and 14±1% in HLS plus diltiazem. The 45Ca activity of CASM was significantly increased by adding HLS, while this elevated 45Ca activity was significantly reduced by adding diltiazem.Based on these data, we conclude that diltiazem suppresses HLS-induced necrosis of cultured aortic smooth muscle cells by reducing intracellular calcium. This mechanism might play an important role in the protection of atherosclerosis by the calcium antagonists.