醋柳黄酮对血管平滑肌细胞胞内游离钙浓度的影响

目的:探讨醋柳总黄酮(TFH) 对血管平滑肌细胞胞内游离钙浓度(Ca²⁺]_i) 的影响。方法:采用新一代钙荧光探针Fluo-3/AM 检测在高钾、去甲肾上腺素(NE)、血管紧张素II(Ang Ⅱ) 刺激下单层兔主动脉平滑肌细胞内游离钙水平的改变, 并与传统的钙拮抗剂Verapamil (Ver) 进行对照研究。结果:TFH(100 mg·L^-1) 对静息状态的血管平滑肌细胞Ca²⁺]_i 无明显影响;TFH(60 ～ 100 mg·L^-1) 呈剂量依赖性抑制高K⁺ 去极化引起的Ca²⁺]_i 升高, 与Ver 作用相似, 但弱于Ver;TFH(80、100 mg·L^-1) 对NE、Ang Ⅱ通过受体介导引起Ca²⁺]_i 升高均具有明显的抑制作用;在无细胞外Ca²⁺存在下, TFH(80、100 mg·L^-1) 对NE 引起的Ca²⁺]_i 升高也具有一定程度的抑制效应。结论:醋柳总黄酮通过对电压依赖性钙通道和受体操纵型钙通道双重抑制降低血管平滑肌细胞内游离钙水平, 这可能是醋柳黄酮产生舒血管降压作用机制之一。

Effects of flavonoids of Hippophae rhamnoides L on intracellular free calcium concentration in cultured rabbit aortic smooth muscle cells

AIM: To explore the effects of total of flavonoid Hippophae rhamnoides L (TFH) on intracellular free calcium (Ca²⁺]_i) in vascular smooth muscle cells (VSMC).METHODS: The cultured rabbit aortic smooth muscle cells were expose to high K⁺, norepinephrine (NE) and angiotensin II(Ang Ⅱ), which were compared with those of verapamil(Ver), and then the changes of Ca²⁺]_i in VSMC were determined by using the new generation of fluorescent Ca²⁺-indicater fluo-3/AM.RESULTS: TFH (100 mg·L ^-1) had no significant effect on therestingCa²⁺]_i.However, and TFH(60 ^-100 mg·L ^-1) inhibited the elevation of Ca²⁺]_i induced by high potassium-depolarization in a concentration-dependent manner. These effects were similar to but weaker than those of Ver.In addition, TFH (80, 100 mg·L ^-1) inhibited the elevation of Ca²⁺]_i induced by NE or Ang II in the presence of extracellular Ca²⁺.In the absence of extracellular Ca²⁺, TFH (80, 100 mg·L ^-1) also had some blocking effects on the NE-induced Ca²⁺]_i increase.CONCLUSION: TFH may decrease the Ca²⁺]_i of VSMCs by blocking both voltage-dependent calcium channels and receptor-operated calcium channels, which may be one of TFH vasodilative and hypotensive mechanisms.