MN9202对离体大鼠胸主动脉的舒张作用及其机制

Vasorelaxing role of MN9202 in rat thoracic artery in vitro

目的 :研究新合成的二氢吡啶类钙拮抗剂 2 ,6 二甲基 4 (3 硝基苯基 ) 1,4 二氢 3,5 吡啶二羧酸 3 甲酯 5 正戊酯 (MN92 0 2 )对离体大鼠胸主动脉的舒张作用及其机制。方法 :采用离体血管灌流的方法 ,观察MN92 0 2对内皮完整和去内皮胸主动脉的舒张作用 ,以及TEA(四乙铵 )对这一过程的影响。结果 :MN92 0 2可引起剂量依赖性的舒张血管效应且无内皮依赖性 ;钙激活钾通道 (KCa)的阻断剂TEA(10 -5mol/L)可减弱 (但不完全阻断 )MN92 0 2舒张血管的作用 ,使量效曲线右移。结论 :MN92 0 2对胸主动脉具有不依赖内皮的舒张作用 ,此作用是通过阻断L 型钙通道的钙内流 ,本研究也证明MN92 0 2舒张胸主动脉作用可能还与KCa有关。

AIM:To investigate the effects and mechanism of methyl pent y1 ,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pridinedicarboxylate (MN92 02, a novel dihydropyidine calcium channel blocker) on blood vessel rings of ra t thoracic arteries. METHODS:Effects of MN9202 on the tension of vascular strips were observed by n vitro perfusion. The effects of TEA were also observed. RESULTS:It was found that MN9202 caused a concentr ation-dependent relaxation in rat thoracic arteries which was independent of th e endothelium. TEA(10 -5mol/L),an antagonist of calcium activated potassiu m channel(K Ca) reduced but not completely blocked the vasorelaxing effec t of MN9202. CONCLUSION: These findings suggest that MN9202 can re lax rat thoracic arteries and the vasorelaxing effect of MN9202 is associated wi th K Ca.