7-甲氧基-4′-羟基-3′-二乙胺甲基异黄酮(MHDF)对大鼠血流动力学和主动脉的作用

本实验观察了MHDF对整体大鼠血流动力学和离体大鼠胸主动脉的作用。结果表明iv MHDF(3～12.8 mg/kg)能降低大鼠左心室±dp/dt_max,V_max,V_pm和LVSP,延长T-dp/dt_max,减慢心率。MHDF还能舒张大鼠胸主动脉,ED₅₀为6.5×10^-6mol/L;非竞争拮抗NA和CaCl₂致主脉收缩,pD₂′为3.11±0.21和3.73±0.07;抑制高K⁺致主动脉收缩,IC₅₀为1.76×10^-5mol/L。提示MHDF对血管的作用与α受体阻断剂不同,而可能与钙拮抗有关。

EFFECTS OF 7 - METHOXY-4'-HYDROXYL - 3'- DIETHYLAMIONOMETHYLISOFLAVONE (MHDF) ON HEMODYAMICS AND AORTA IN RATS

MHDF is a synthetic isoflavone derivative with anti-ischemic effect. In this paper, the effects of MHDF on in vivo hemodynamics and in vitro contraction of rat aorta were reported. MHDF (3-12.8 mg/kg) was found to decrease +/- dP/dtmax, Vmax, Vpm and LVSP, prolong T-dP/dtmax of left ventricle and slow the HR in rats. It was also shown to inhibit the changes of heart performance induced by CaCl2 in rats. In isolated rat aorta, MHDF caused a noncompetitive antagonism of noradrenaline-and CaCl2-induced contraction with the pD2' of 3.11 +/- 0.21 and 3.73 +/- 0.07. The high K(+)-evoked contraction with IC50 of 17.6 mu mol/L was also found to be inhibited. The results suggest that the effect of MHDF on vascular muscle is different from that of an alpha-blocker and may be attributable to inhibition of extracellular calcium influx or intracellular calcium release.