维药唇香草醇提物对大鼠离体胸主动脉血管环的舒张作用

Vasodilatation Effects of the Alcohol Extract from Uighur Medicine Ziziphora clinopodioides on Isolated Rat Thoracic Aorta Vessel Rings

目的:研究唇香草醇提物(EEZ)对大鼠离体胸主动脉血管环的舒张作用。方法:制备大鼠离体胸主动脉血管环。试验设内皮完整组与内皮去除组,以去氧肾上腺素(PE)预收缩血管环后逐步累积加入100、300、500、700、900、1 100 mg/L EEZ,绘制浓度-张力曲线并计算最大舒张率(Emax)、半数有效浓度(EC50)。试验只设血管环内皮去除组,在无钙或无钙高钾液中以EC50的EEZ预处理血管环后逐步分别累积加入0.4、0.8、1.2、1.6、2.0、2.4 mmol/L Ca Cl2,绘制钙浓度-张力曲线;以EC50的EEZ预处理血管环后加入1μmol/L PE记录收缩张力并计算血管收缩百分率。结果:EEZ对PE预收缩的血管环具有浓度依赖性和平滑肌依赖性的舒张作用;内皮完整组与内皮去除组Emax分别为(58.18±16.23)%与(73.54±17.21)%,EEZ的EC50为773.27 mg/L。在无钙高钾液中,EEZ可以明显引起钙离子收缩曲线右移;在无钙液中,EEZ对PE引起的血管收缩具有抑制作用。结论:EEZ具有血管舒张作用,其机制可能是通过抑制电压依赖性钙通道(VDCCs)的方式来抑制外钙内流和胞质内钙释放,从而干扰胞质内钙离子平衡。

OBJECTIVE：To study the vasodilatation effects of the alcohol extract from Uighur medicine Ziziphora clinopodioi-des（EEZ）on isolated rat thoracic aorta vessel rings. METHODS：Isolated rat thoracic aorta vessel rings were prepared. There was a group with intact vessel ring endothelium and a group with vessel ring endothelium removed in the test. After preshrinking the ves-sel rings with phenylephrine（PE）,EEZ of 100,300,500,700,900 and 1 100 mg/L was added gradually,concentration-vasodila-tation curve was drawn and maximal vasodilatation rate （Emax） and median effective concentration （EC50） were calculated. For the group with vessel ring endothelium removed,after the vessel ring was pretreated with EEZ at EC50 in calcium-free solution or calci-um-free high-potassium solution,CaCl2 of 0.4,0.8,1.2,1.6,2.0 and 2.4 mmol/L was added gradually,and calcium concentra-tion-tension curve was drawn;following the pretreatment of the vessel ring with EEZ at EC50,1 μmol/L PE was added and shrink tension was recorded and vasoconstriction percentages was calculated. RESULTS：EEZ had vasodilatation effect on the vessel ring preshrunk with PE in a concentration and smooth muscle-dependent manner. The group with intact vessel ring endothelium and the group with vessel ring endothelium removed respectively had Emax of （58.18 ± 16.23）% and （73.54 ± 17.21）%,and EEZ EC50 of 773.27 mg/L. For calcium-free high-potassium solution,EEZ could cause the calcium ion-vasoconstriction curve to move to the right obviously;for calcium-free solution,EEZ could inhibit the vasoconstriction caused by PE. CONCLUSIONS：EEZ has vasodi-latation effects by a mechanism which may be related to inhibiting calcium influx and intracytoplasmic calcium release through the inhibition of voltage-dependent calcium channels（VDCCs）,and thus interfering intracytoplasmic calcium ion balance.