EMD_(56431)对犬冠脉和肠系膜动脉的作用

Action of EMD_(56431) on isolated canine coronary and mesenteric arteries

研究表明：①0．7μmol／LEMD对20mmol／LKCl去极化冠脉（＋E，－E）呈非内皮依赖性松弛，而对60mmol／LKCI去极化冠脉则无效。②格列本脉能有效桔抗EMD对冠脉的松弛作用。③EMD可使低浓度KCl去极化思脉量效曲线呈非平行右移，拮抗作用明显，但对高浓度KCl刚失去拮抗作用，最大反应（Emax）不压低。④EMD松弛犬肠系膜动脉及冠脉的EC50（－LogC）分别为6．2和644。

<Abstratc>The action of EMD56431 (EMD) on isolated canine coronary and mesenteric arteries was inves-tigated, in the canine left circumflex of the coronary artery rings with or without endothelium 0.7 pmol/LEMD caused to be relaxed by pre-constricted with 20 mmol/L KCl. When 60 mmol/l KCl was used, therelaxation of EMD was abolished. In the presence of glibenclamide the vasolaxant response to EMD in KClcon8tracted coronary artery was antagonised significantly, EMD nonparallelly shifted the dose-responsecurves for KCl-induced contraction to the right, but it was only able to reduce the c0ntracted response tolOw concentration of KCl (5 ~ 30 mmol/L), the maximal response was not lowered. EMD produced amarkedly dose-depended reduction of contractile response to phenylephrine in mesenteric artery or KCl incoronary artery, their-Log EC50 values were 6. 20 and 6. 44 respectively.