活血逐瘀方浸膏的舒张血管作用及其作用机制

目的观察活血逐瘀方浸膏的舒张血管作用，并探讨其作用机制。方法采用豚鼠肠系膜微血管和大鼠体外主动脉环研究活血逐瘀方浸膏舒张血管作用;硝酸还原酶法测定血浆一氧化氮(NO)和血管NO、一氧化氮合酶(NOS)、原生型一氧化氮合酶（cNOS）及诱生型一氧化氮合酶（iNOS）的活性。结果活血逐瘀方浸膏有抗去甲肾上腺素致豚鼠肠系膜微血管收缩的作用;松弛苯肾上腺素引起体外大鼠胸主动脉环收缩的作用，预加格列本脲或普萘洛尔后仍然有松弛作用，而去内皮后引起收缩作用;高剂量的活血逐瘀方浸膏非常显著性地升高血浆NO及主动脉NO含量、提高NOS和cNOS的活性;低剂量活血逐瘀方浸膏显著性提高血管cNOS的活性。结论活血逐瘀方浸膏有舒张血管的作用，其作用机制可能与其激活血管NOS、cNOS活性和促进血管内皮NO释放有关。

Vasodilative Effect of the Extract of Huoxuezhuyu Recipe and Its Underlying Mechanisms

Objective To survey the vasodilative effect of the extract of huoxuezhuyu recipe and to probe into its underlying mechanisms. Methods The vasodilative effect of the drug was studied with the guinea pig mesenteric microvasculature and isolated rat aortic rings. The content of nitric oxide(NO )in the blood plasma and aortic tissue, the activities of nitric oxide synthase (NOS) , constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) in the aortic tissue were determined with the method of nitroreductase chromatometry. Results The extract of huoxuezhuyu recipe was shown to counteract the vasocontrictive effect of norepinephrine on the mesenteric microvasculative of the guinea pig. It could also relax the isolated rat aortic rings constricted by phenylephrine. The vasorelaxing effect of the extract persisted despite pretreatment of the aortic rings with glibenclamide or propranolol. However, the extract of huoxuezhuyu exerted vasoconstrictive effect on the aortic rings if the endothelium had been denuded. The extract in high dose was shown to very significantly increase the content of NO in the blood plasma and the content of NO as well as the activities of NOS and cNOS in the aortic tissue. In contrast, the extract in low dose could significantly increase the activity of cNOS in the aortic tissue. Conclusion The extract of huoxuezhuyu recipe was shown to have a vasodilative effect and its underlying mechanisms may be related to the activation of the vascular NOS and cNOS as well as the promotion of the release of NO from the endothelium of the blood vessel.