论文部分内容阅读
目的:研究甲基原薯蓣皂苷(MPD)对大鼠心肌细胞内钙浓度([Ca2+]i)的活动及细胞膜ATP酶功能的影响,并分析其机制。方法:将乳鼠心肌细胞悬液随机分为对照组、MPD组、地尔硫卓(Dil)组,荧光分光光度计法观察心肌细胞[Ca2+]i的变化。将培养的乳鼠心肌细胞分为对照组和MPD组,分别检测心肌细胞膜ATP酶活性,并观察肌浆网钙ATP酶SERCA2a基因的mRNA表达水平。结果:在静息状态下,各组的心肌细胞[Ca2+]i均无显著性差异。但在KCl刺激下,MPD和Dil组与对照组相比,荧光信号峰值和[Ca2+]i浓度均低于对照组(P<0.001)。在心肌细胞膜ATP酶的活性中,MPD组的Na+-K+-ATP酶和Ca2+-Mg2+-ATP酶的活性显著高于对照组(P<0.05,P<0.01),而Mg2+-ATP酶的活性在2组间的比较无差异性。MPD组与对照组2组SERCA2a的mRNA表达量也无差异性。结论:MPD在一定程度上可以抑制细胞膜上电压依赖型钙通道开放,减少钙离子内流。MPD还可以通过提高心肌细胞膜钠泵和钙泵功能,影响心肌细胞钙离子跨膜转运,维持细胞内低钙离子的环境。
OBJECTIVE: To investigate the effect of methyl protodiones (MPD) on the activity of intracellular calcium concentration ([Ca2+]i) and the function of cell membrane ATPase in rat cardiomyocytes, and to analyze its mechanism. Methods: The neonatal cardiomyocyte suspension was randomly divided into control group, MPD group and diltiazem group. The changes of [Ca2+]i in cardiomyocytes were observed by fluorescence spectrophotometry. The cultured neonatal rat cardiomyocytes were divided into control group and MPD group. The ATPase activity of myocardial cell membrane was detected, and the mRNA expression level of sarcoplasmic reticulum calcium ATPase SERCA2a gene was observed. RESULTS: At resting state, there was no significant difference in [Ca2+]i of myocardial cells in each group. However, compared with the control group, the fluorescence signal peak and [Ca2+]i concentrations in the MPD and Dil groups were lower than those in the control group (P<0.001). In the activities of myocardial cell membrane ATPase, the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in the MPD group were significantly higher than those in the control group (P<0.05, P<0.01), and the activity of Mg2+-ATPase was There was no difference between the two groups. There was no difference in mRNA expression of SERCA2a between the MPD group and the control group. CONCLUSION: MPD can inhibit the opening of voltage-dependent calcium channels on the cell membrane to a certain extent and reduce the influx of calcium ions. MPD can also affect the calcium ion transmembrane transport of myocardial cells by maintaining the function of sodium pump and calcium pump of myocardial cell membrane, and maintain the environment of low calcium ion in cells.