采用雄性大鼠胸主动脉环，研究灯盏花素舒张血管的机制。结果表明，灯盏花素（1×10^－6mol/L～1×10^－3mol/L）对去甲肾上腺素（1×10^－6mol/L）的收缩反应呈剂量依赖性的松弛作用，与内皮无关，也不受普萘洛尔（1×10^－6mol/L）所影响。灯盏花素能拮抗去甲肾上腺素诱发的依外钙与依内钙的双相反应，而且对后者的抑制作用较强。揭示灯盏花素诱发血管舒张可能与受体操纵性钙通道和细胞内Ca²⁺释放的抑制有关。灯盏花素作用后不同时间未引起肌条cAMP、cGMP含量的规律性改变。在高钾所致的主动脉环收缩反应中，灯盏花素在正常的Kred’s液中表现出兴奋作用，不受酚妥拉明（1×10^－5mol/L）影响。

The relaxation effect of Breviscapine on isolated thoracic aortic ring of rat was studied. The results indicated that Breviscapine (1×10^－6mol/L~ 1 ×10^－3mol/L) could relax NE-induced vasoconstriction in a concentration-dependent manner. It was independent to endothelium and could not be influenced by 1 ×10^－5 mol/L propranolol. Breviscapine could antagonize NE-induced biphase contractive responses, which were dependent to extracellular and intracellular calcium, but the antagonistic effect of the later was stronger than that of the former. The results suggested that vasodilation effect of Breviscapine might be related to the inhibition of the receptor-operated calcium channel and intracellular Ca²⁺ release. Breviscapine, at different time of its action, did not cause any regulatory changes of cAMP and cGMP content in the muscular strips,suggesting that relaxation effect of Breviscapine was independent to cAMP and cGMP. Breviscapine had an exciting action on the high K+ evoked-contraction of the aortic ring in normal Kreb's solution, that could not be influenced by phentolamine (1 ×10^－5 mol/L). The mechanism of this phenomenon remained to be studied.