Action of EMD_(56431) on isolated canine coronary and mesenteric arteries
Yang Xinghai; Han Yu and Zhang Ying(Medical College,Hubei Sanria Xueyuan, Yichang 443003)
AbstratcThe 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.