Relationship between vasodilatation effect of daidzein and vascular endothelium / 中国药理学通报

ABSTRACT

Aim To study the relationship between the vasodilatation effects of daidzein and M-receptor in the endothelial cell, extracellular Ca2+ and intracellular Ca2+.Methods Measurement of isometric force of rabbit thoracic aortae rings was performed. Results Dai(3～100 ?mol?L-1 ) significantly inhibited the contractive response of phenyleohrine dependent on intracellular Ca2+ release and extracellular Ca2+ inflow;a shift was produced to the right of the concentration-effect curve of KCl and the maximum response was depressed by Dai(10～100 ?mol?L~ -1 ); Dai(10,30,100 ?mol?L-1 ) enhanced the relaxing effect induced by acetylcholine in a concentration-dependent manner,but the relaxing effect was inhibited after using atropine to block the M-receptor. Conclusion The relaxing effect of Dai was related to the inhibition of the receptor-mediated Ca2+ -influx and Ca2+-release;Dai induced direct relaxing effect by activating the M-receptor in the endothelium and releasing EDRF, which was similar to ACh, and this effect was endothelium-dependent.