山楂总黄酮对大鼠离体血管功能的影响及其机制

Effects and Mechanisms of Hawthorn Flavonoids on Vessel Function in Isolated Rat Aortic Rings

关键词:  山楂总黄酮  血管舒张  胸主动脉环

Key words:  hawthorn flavonoid  vasodilation  thoracic aortic ring

摘要:

目的 研究山楂总黄酮对大鼠离体血管功能的影响，并初步探讨其作用机制。方法 采用大鼠离体血管灌流模型，观察山楂总黄酮对大鼠离体血管舒张和收缩功能的影响。结果 山楂总黄酮对大鼠离体血管具有浓度依赖性地舒张作用，还可浓度依赖性地抑制苯肾上腺素、CaCl2引起的血管收缩，对无钙液中肾上腺素引起的血管收缩也有抑制作用。非选择性钾通道抑制剂、内向整流钾通道抑制剂可部分阻断山楂总黄酮引起的血管舒张作用。结论 山楂总黄酮对大鼠离体血管具有舒张作用，该作用主要是通过抑制细胞外Ca2+内流，抑制细胞内贮Ca2+释放，以及激活非选择性钾通道和内向整流钾通道来实现的。

Abstract:

OBJECTIVE To investigate the effects and mechanisms of hawthorn flavonoids on vessel function in isolated rat aortic ring. METHODS To observe the effect of hawthorn flavonoids on isolated rat vascular diastolic and systolic function by building isolated rat vascular perfusion model. RESULTS Hawthorn flavonoids produced a dose-dependent vasodilation with or without endothelium. Pre-incubation with hawthorn flavonoids could inhibit vessel contraction induced by phenylephrine in a concentration-dependent way. Hawthorn flavonoids inhibited phenylephrine-induced and CaCl2-induced vasoconstriction in Ca2+-free medium. Pre-incubation with tetraethylammonium, a non-selective K+ channel blocker, and BaCl2, an inward rectifier K+ channel blocker, partially antagonized the relaxation response induced by hawthorn flavonoids. CONCLUSION Hawthorn flavonoids shows a endothelium-independent effect in isolated rat thoracic aortae mainly through blocking calcium influx and inhibiting intracellular calcium release, as well as opening non-selective K+ channel and inward rectifier K+ channel in the vascular smooth muscle cells.