红花水煎剂对家兔离体主动脉血管的舒张作用

目的　观察红花Carthamustinctorius (DFCT)水煎剂对血管肌条的舒张作用及机制。方法　将家兔离体主动脉肌条放置于灌流肌槽中 ,记录其等长收缩。结果　DFCT对血管肌条静息张力无明显影响 ,但 2 0mg/mLDFCT水煎剂与 10 -5mol/L乙酰胆碱相似 ,可使 10 -6mol/L去甲肾上腺素预收缩血管肌条产生明显的舒张作用。去除内皮细胞、10 -4mol/LL NNA或 10 -5mol/L甲烯蓝可减弱DFCT的舒张血管作用 ,但前列腺素合成抑制剂和 β肾上腺素能受体阻断无明显影响。另外 ,4 0mg/mLDFCT水煎剂可明显抑制去内皮血管肌条去甲肾上腺和KCl的量效收缩反应 ,使其PD2 值分别由对照组 6 0 6± 0 0 9和 1 71± 0 33变为 5 0 7± 0 0 8和 1 35± 0 2 0。结论DFCT水煎剂可通过受体操纵Ca2 + 通道和电压依赖性Ca2 + 通道抑制外Ca2 + 内流 ,使血管肌条舒张 ,其作用与内皮释放的NO有关。

Vasodilatory effect of water decoction of dried flower of Carthamus tinctorius on rabbit aorta in vitro

Object To observe the vasodilatory effect of a water decoction of the dried flower of Carthamus tinctorius L. (DFCT) on rabbit thoracic aorta and its mechanism. Methods Strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb's solution, and then isometric tension was measured. Results DFCT did not change the resting tension of rabbit aortic strips. But similar to Ach (10-5 mol/L), DFCT (20 mg/mL) could cause an obvious relaxation in 10-6mol/L NA-precontracted arterial strips. The relaxant effect of DFCT was significantly reduced by removal of endothelium and 10-4mol/L L-NNA and 10-5mol/L methylene blue but not by prostaglandin synthase inhibitor and blockage of adrenergic β receptor. In addition, DFCT (40 mg/mL) inhibited NA and KCl cumulative concentration-response curves of aortic strips without endothelium, and changed the PD2 values for NA from (6.06±0.09) in control group to (5.07±0.08) and for KCl from (1.71±0. 33) in control group to (1.35±0.20),respectively. Conclusion These results suggest that the vasodilatory effect of DFCT in rabbit thoracic aorta may be related to the nitric oxide release from endothelium, and also probably due to inhibition of Ca2+ influx through receptor-operated and voltage-dependent calcium channels.