摘要
目的探讨钙依赖的信号转导途径在神经肽Y诱导心肌细胞肥大中的作用.方法用NPY刺激Wistar 乳鼠心肌细胞,并用Ca2+/CaM依赖的钙调神经磷酸酶(CaN)的特异性抑制剂环胞素A(CsA)加以干预.应用3H—Leu 掺入量法测定心肌细胞蛋白质合成速率,用Fluo3-AM荧光标记细胞内游离钙离子,观察不同作用时限内心肌细胞胞浆及核内钙离子浓度变化.结果①心肌细胞3H-Leu掺人量测定:与对照组相比,NPY10nM组3H-Leu掺入量有所增高,但与对照组比无显著差异,而NPY100nM组心肌细胞3H—Leu掺入量较对照组明显增高(p<0.05).CsA组和对照组相比无显著差异.②加入100nmol/L NPY即刻至10min内,心肌细胞胞浆及核内钙含量均无显著差异.经100nmoL/L NPY刺激24h后,心肌细胞胞浆及核内钙含量明显高于对照组(p<0.001,p<0.001).结论NPY刺激心肌细胞蛋白质合成增加,提示NPY可诱导心肌细胞肥大;CaN抑制剂CsA可阻断NPY上述效应,说明Ca2+/CaM依赖的CaN信号途径在其中起重要作用.较长时间的NPY刺激可导致心肌细胞胞浆及核内钙Ca2+浓度增加,这可能是活化CaN信号途径的始动环节.
Objective To investigate the role of Calcium signal on cardiomyocytes hypertrophy of rat caused by neuropeptide Y （NPY）. Methods Cardiomyocytes of neonatal Wistar rats were cultured with NPY with various concentrations （10 nmol/L, 100 nmol/L）. Cyclosporine A（CsA） was used to inhibit the activity of CaN. For assessing protein synthesis rate and [Ca^2＋]i in cardiomyocytes,the methods of 3H - Leu incorporation and fluorescent assay with Fluo3 - AM were used. Results ① The [Ca^2＋ ] inplasmas and nuclear of cardiomyocytes： 24 hours after incubation, the [Ca^2＋] in plasmas and nuclear in NPY（100nm） group was significantly elevated compared with control group （p 〈 0.001 ）. ② 3H- Leu incorporation in cardiomyocytes- 3H- Leu incorporation in NPY（ 10 nmol/L） group was higher than in control group, but there were no distinct changes between two groups. To compare with control group, 3H - Leu incorporation in NPY（ 100 nmol/L） group were increased significantly （p 〈 0.05）. The effects of NPY（ 100 nmol/L） were blunted by CsA. Conclusions The result suggested that NPY could induce hypertrophy of cardiomyocytes, and Ca^2＋/CaM- dependent CaN signal pathway carries out an important role in it. The enhancement of [Ca^2＋]i caused by NPY may activate CaN signal pathways to mediate cardiac hypertrophy.
出处
《现代临床医学生物工程学杂志》
2005年第3期176-178,共3页
Journal of Modern Clinical Medical Bioengineering
基金
广东省自然科学基金资助项目(No.031715)
