去氢紫堇碱对大鼠离体胸主动脉平滑肌的作用(英文)

去氢紫堇碱 (DHC) 12 .5～ 2 0 0 μmol·L- 1对大鼠离体胸主动脉环由去甲肾上腺素 (NE) ,KCl,CaCl2诱发的收缩反应均呈非竞争性拮抗作用 ,pD′2 分别为 5 .12 ,3.83和 3.4 9,且DHC的该松弛作用与血管内皮细胞无关 .DHC对NE诱发的血管平滑肌两种成分的收缩均呈显著抑制作用 ,与经典钙拮抗剂维拉帕米相似 .结果提示DHC对血管平滑肌的松弛作用与外钙内流及内钙释放均密切相关 .

Effect of dehydrocorydaline on isolated thoracic aorta in rats

The relaxant effect and its mechanism of dehydrocorydaline(DHC) was studied on the isolated thoracic aorta rings in rats. DHC showed relaxant effects on thoracic aorta with intact or without endothelium. The contraction responses induced by norepinephrine(NE), KCl, and Ca²⁺ was antagonized by 12.5 to 200 μmol·L^-1 DHC in a non- competitive manner. The pD′₂ values were 5.12, 3.83, 3.49, respectively. In Ca²⁺ free modified Krebs solution, the contraction of two components induced by NE were inhibited significantly by 25 μmol·L^-1 DHC. The effect features of DHC mentioned above were just like that of verapamil in the same experimental conditions. The results suggest that the relaxant effect of DHC on rat′s thoracic aorta be not dependent on endothelium, and be closely related to the blockage of Ca²⁺ entry through both potential-dependent calcium channel and receptor- operating calcium channel, and to the inhibition of intracellular Ca²⁺ release.