激光共聚焦显微镜比较观察甾体皂苷Trilliuo、Lc253、Lc239对培养心肌细胞内[Ca2+]i的作用

目的：薯蓣皂苷元的皂苷为许多抗心血管中药中的主要活性成分，具有重要研究价值。本研究以经人工合成获得的薯蓣皂苷元皂苷同系物甾体皂苷Trilliuo(署蓣皂苷元葡萄糖苷、Lc253薯蓣皂苷鼠李糖(1→2)葡萄糖苷]、Lc239(薯蓣皂苷元鼠李糖(1→2)，葡萄糖(1→3)]葡萄糖苷)为研究对象，通过考察它们对培养心肌细胞钙离子释放的影响，分析其构效关系。方法：利用激光共聚焦显微镜测定加入fluo3—AM培养的心肌细胞中的钙离子变化情况。结果：Lc253能明显增强心肌细胞节律性和呈浓度依赖性增加心肌细胞静息钙离子水平，加入CaCl2 10mmol/L or KCl 60 mmol/L后钙离子荧光峰强度仍维持在较高水平；而Trilliuo and Lc239在10^—5mmol/L浓度时，对心肌细胞静息钙离子水平作用不明显，在高浓度胞外Ca^2 或K^ 情况下，抑制心肌细胞内钙离子升高；其作用特点与verapamil相似，具有钙离子通道阻断作用。结论：研究结果显示三种甾体皂苷对细胞内钙离子浓度有所差异，结构中连接糖的数目与调孔钙内流的活性有重要的相关性。这些皂苷类化合物对钙离子通道的活性有潜在的开发价值。

Comparison of Intracellular Ca2+ Patterns Affected by Steriod Saponin Trilliuo, Lc253 and Lc239 in Cultured Cardiomyocytes Revealed by Confocal Microscopy

AIM:To study the effects of Trilliuo, Lc253 and Lc239, which belong to a group of structurally similar diosgenyl saponins, on Ca + release in cultured primary rat cardiomyocytes. METHOD: Cardiomyocytes were cultured and loaded with fluo3-AM. Ca2 + ]; was measured by fluorescent intensity in each cell with laser confocal microscopy. RESULT: Lc253 enhanced the frequency from 10+2 to 20+3 beat/min, and simultaneously induced a very obvious increase in the peak fluorescent intensity (pFI) of Ca2+ ]; in a concentration-dependent manner: the pFI was maintained at a high level followed by addition of CaCl2 10 mmol/L or KC1 60 mmol/L. However, Trilliuo and Lc239 10 mmol/L, which had little effect on spontaneous Ca2 + release activity, prevented the increase in frequency and pFI of Ca + oscillation caused by high extracellular Ca2+ or K+ . These actions were similar to those in verapamil-treated cells showing q calcium channel blocking affect. CONCLUSION: These results indicated that the different actions of three saponins on intracellular Ca2+ patterns are associated with their structure, and number of sugar residues in the sugar chain which seems to play an important role to regulate Ca 2+ influx. These saponins are potential for their effects on Ca2+ channels of cardiomyocytes.