葛根总黄酮对离体神经肽Y诱导的心肌细胞肥大的影响

目的:观察葛根总黄酮对离体神经肽Y(NPY)诱导的心肌细胞肥大效应的影响。方法:建立体外培养的大鼠心肌细胞培养体系,实验分(1)对照组、(2)NPY组:加入终浓度为100 nmol/L的NPY、(3)NPY+葛根总黄酮4个浓度组:分别加入100 nmol/L NPY和0.5 mg/L、1 mg/L、2 mg/L、3 mg/L的葛根总黄酮。应用氚-亮氨酸([³H-Leu])掺入法测定心肌细胞蛋白合成率;RT-PCR法测心肌细胞C-jun mRNA表达;组织化学法测心肌钙调磷酸酶(CaN)活性。结果: NPY组心肌细胞[³H-Leu]掺入量为896±34;C-jun mRNA表达为23 132.62±1 787.28;CaN活性为35.62±4.60,与对照组(分别为[³H-Leu]752±46、C-jun mRNA 17 819.49±1 452.06、Can22.94±6.20)相比有显著差异(P＜0.01、P＜0.05)。而葛根总黄酮1-3 mg/L可使在NPY作用下的心肌细胞[³H-Leu]掺入量下降(3个剂量组分别为797±78、772±58、786±43);C-jun mRNA表达减少(分别为18 035.32±1 592.23、18 043.90±1 726.19、18 072.29±1 692.34);CaN活性降低(分别为28.34±6.40、25.69±5.90、26.37±3.50)与对照组相比无显著差异(P＞0.05)。结论:NPY可诱导心肌细胞肥大;葛根总黄酮在1-3 mg/L浓度可阻断其效应,其作用可能与抑制CaN活性、阻断Ca²⁺/CaM依赖的CaN信号途径有关。

Effects of pueraria lobata isoflavones on myocardiac cell hypertrophy induced by neuropeptide- Y in vitro

AIM: To investigate the effects of pueraria lobata isoflavones (PLIs) on neuropeptide-Y(NPY)-induced myocardiac cell hypertrophy in vitro. METHODS: Rat cardiomyocytes cultured in vitro were randomized to control, NPY, NPY PLIs and PLIs group. The protein synthesis in cardiomyocytes was assessed by [~3H-Leu] uptake, C-jun mRNA by RT-PCR and CaN activity by histochemistry. RESULTS: The rate of [~3H-Leu] uptake, the C-jun mRNA expression and the CaN activity of myocardiac cells in 100 nmol/L NPY group were higher than those in control (P<0.01,P<0.05). On the other hand, the effects of NPY on myocardiac cells in vitro were inhibited by PLIs at concentrations of 1-3 mg/L.CONCLUSION: NPY could induce the myocardiac cell hypertrophy in vitro, which was inhibited by PLIs. The underlying mechanism may be attributed to the inhibition of CaN activity and blocking of Ca~(2 )/CaM-dependent pathway. [