附子水煎剂对家兔离体肺动脉血管的舒张作用

Vasodilation in vitro of water decoction of Monkshood Root on rabbit pulmonary artery

目的:研究附子MonkshoodRoot(DMR)水煎剂对肺动脉环的舒张作用及机制。方法:采用家兔离体肺动脉平滑肌标本,以去甲肾上腺素(NA)预收缩肺动脉后,给予不同剂量的附子观察其张力变化,并探讨去除血管内皮、给予NO合酶抑制剂左旋硝基精氨酸(L-NNA)、甲烯蓝(MB)、环氧酶抑制剂吲哚美辛和β肾上腺素能受体阻断剂普萘洛尔对血管张力变化的影响。结果:附子对血管环静息张力无明显影响,但不同剂量的附子可使10-6mol·L-1NA预收缩血管产生明显舒张(r=0.71,P<0.001)。去除血管内皮、10-4mol·L-1L NNA或10-5mol·L-1MB可减弱附子的舒张作用。另外,1mg·mL-1DMR对无内皮血管环NA和KCl的量效曲线无明显影响,DMR温育前后NA的PD2值为7.56±0.95和7.30±0.83,P>0.05;KCl的PD2值为1.74±0.48和1.71±0.51,P>0.05。结论:附子水煎剂对肺动脉的舒张作用是内皮依赖性,与内皮细胞释放的NO有关,而与平滑肌细胞膜上的受体依赖性Ca2+通道和电压依赖性Ca2+无关。

AIM: To study vasodilating effect of a water decoction of Monksbood Root (DMR) on rabbit pulmonary artery rings and its mechnism. METHODS: In noradrenaline (NA) precontracted isolated pulmonary artery in rabbit, the response to different concentrates of DMR was investigated; the effects of removal of endothelium and in, coincubation with nitric oxide synthase inhibitor N~ω-nitro-L-arginine (L-NNA), methylene blue (MB), prostaglandin synthase inhibitor and blockage of the adrenergic, β-receptor on DMR-induced relaxation, blood vessel tension were also assessed. RESULTS: DMR did with different concentrate did not change the resting tension of rabbit pulmonary artery rings but could cause an obvious relaxation in 10^(-6)mol/L NA-precontracted pulmonary artery rings (r=0.71, P<0.001). The relaxant effect of DMR was significantly attenuated by removal of endothelium, 10^(-4) mol/L L-NNA and 10^(-5) mol/L MB. In addition, DMR (1 mg/mL) did not inhibit NA and KCl cumulative concentration response curves of pulmonary artery rings without endothelium, and did not change the PD_2 values for NA from (7.56±0.95) in control group to (7.30±0.83, P>0.05) and for KCl from (1.74±0.48) in control group (1.71±0.51, P>0.05) respectively. CONCLUSION: DMR can relax isolated rabbit pulmonary artery on the basis of endothelium-dependent and may involve in nitric oxide (NO), but is not related to blockage of receptor-operated and voltage-dependent calcium channels.