Vasodilatory effects and mechanism of kaempferol on isolated thoracic aorta of SD male rats
Objective To explore the vasodilatory effects and mechanism of kaempferol(Ka)on isolated tho-racic aorta of SD male rats.Methods The effect of Ka on the vascular ring tension in isolated thoracic aorta was evaluated by using a multi-channel isolated vascular tone measurement system(DMT 620M)based on the vascular ring relaxation rate.N-nitro-L-arginine methyl ester hydrochloride(L-NAME),indomethacin(IMC),4-aminopyr-idine(4-AP),tetraethylamine(TEA),barium chloride(BaCl2)and glibenclamide(GLB)were used to preincubate the vascular ring of isolated thoracic aorta.Norepinephrine(NE)was used to precontract the vascular ring to ex-plore the mechanism of Ka vasodilation on isolated thoracic aortic rings.Molecular docking was used to predict the binding sites of potassium channels linked by Ka.Results Ka can effectively dilate the NE precontracted vascular ring.The above instrumental drugs can counteract the vasodilatory effects of Ka to some extent(P＜0.05).Among them,TEA had the greatest effect on the vasodilatory effect of Ka(mean diastolic rate was 20.51％±7.89％vs.56.78％±2.04％of control group),while GLB had the least effect on the vasodilatory effect of Ka(mean diastolic rate was 42.64％±4.08％in the control group vs 56.78％±2.04％of control group).Molecular docking results showed that the binding free energy of Ka with seven potassium channel target proteins is lower than 5.0 kcal/mol,and that with ATP sensitive inward rectifier potassium channels 8 is the smallest,at-8.6 kcal/mol;the maximum binding free energy with inward rectifier potassium channel 2 is-6.5 kcal/mol.Conclusion Kaempferol can dilate the vascular ring of isolated thoracic aorta in male rats,and the mechanism of action may be related to its depen-dence on vascular endothelium and four types of potassium channels.
NETL
NSTL
万方数据
