[关键词]
[摘要]
目的 研究黄芪多糖对脂多糖(LPS)诱导的大鼠心肌细胞肥大的保护作用。方法 新生1~2 d的SD大鼠心肌细胞培养48 h后,设对照组,模型组,黄芪多糖低、中、高质量浓度(1、10、100 mg/L)组。计算机图像分析系统测量细胞体积;RT-PCR法检测心房利钠多肽(ANP)mRNA的表达;ELISA法检测细胞肿瘤坏死因子-α(TNF-α)的量;采用Fluo-3/Am荧光染色剂负载细胞,在激光共聚焦显微镜下测定细胞内钙离子浓度([Ca2+]i)的瞬间变化。结果 与对照组相比,LPS 1 mg/L可使心肌细胞体积显著增大,ANP mRNA的表达显著增强,细胞分泌TNF-α蛋白的量显著增加,心肌细胞内[Ca2+]i瞬间峰值增大(P<0.01)。与模型组相比,黄芪多糖1、10、100 mg/L预先给药均可抑制心肌细胞体积增大;细胞产生的TNF-α显著减少,ANP mRNA的表达不同程度地减少(P<0.05),其中10、100 mg/L组这两项指标可恢复到对照组的水平(P>0.05);黄芪多糖10 mg/L可拮抗LPS对正常心肌细胞内[Ca2+]i瞬间变化幅度增大的作用(P<0.01)。结论 黄芪多糖对LPS诱导的乳鼠心肌细胞肥大有良好的保护作用,其机制可能与抑制TNF-α的产生、降低[Ca2+]i有关。
[Key word]
[Abstract]
Objective To investigate the protective effect of astragalus polysaccharide (APS) on lipopolysaccharide (LPS)-inducedcardiac myocytes hypertrophy of rats and its mechanism. Methods Cardiac myocytes of 1—2 d neonatal SD rats were cultured 48 hin vitro, and divided into control, model (LPS 1 mg/L) group, APS low-, middle-, and high- (1, 10, and 100 mg/L) groups. Thecardiomyocyte volume was assayed by computer photograph analysis; atrial natriuretic peptide (ANP) mRNA expression wasmeasured by RT-PCR; and tumor necrosis factor-α (TNF-α) level was determined by ELISA. The transient peak change of intracellularcalcium concentration ([Ca 2+ ] i ) was measured by using Fluo-3/Am fluorescent dye load cell under laser confocal microscope. ResultsCompared with control group, LPS 1 mg/L could make the volume of myocardial cells, ANP mRNA expression, the release of TNF-αprotein, and [Ca 2+ ] i transient peak increase significantly (P < 0.01). Compared with the LPS model group, APS pre-administrated at theconcentrations of 1, 10, and 100 mg/L could inhibit myocardial cell volume increase, while cells of TNF-α were significantly reduced,ANP mRNA expression decreased in varying degrees (P < 0.05). APS 10 and 100 mg/L groups could be restored to normal levels of thecontrol group (P > 0.05) and APS 10 mg/L could antagonize transient changes in amplitude increase of [Ca 2+ Conclusion APS does have a good protection on cultured cardiac myocytes hypertrophy and its mechanismmay be related to the inhibition of [Ca 2+ ] i .
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[基金项目]
国家自然科学基金资助项目(30973898/C190702)