摘要
目的观察腺苷A1受体激活在钙调磷酸酶(CaN)通路上对异丙肾上腺素(Iso)诱导的心肌细胞肥大的抑制作用及机制。方法体外培养大鼠乳鼠心肌细胞,以Iso 10μmol.L-1诱导心肌细胞肥大,观察腺苷A1受体激动剂R(-)-N6-(2-phenylIsopropyl)adenosine(R-PIA)1μmol.L-1对其作用,进一步探讨钙调神经磷酸酶特异性抑制剂环孢菌素A(CSA)1μmol.L-1、PKA抑制剂cAMP三乙胺盐(RP-cAMPS)1μmol.L-1、百日咳毒素(PTX)5 mg.L-1存在时,腺苷A1受体的激活对心肌细胞肥大的影响。通过Lowry法测心肌细胞蛋白含量;RT-PCR法检测心肌细胞心钠素(ANP)的mRNA表达;Western blot法测心肌细胞CaN的相对表达水平;以Fluo-3/AM为荧光探针,共聚焦显微镜下测量心肌细胞[Ca2+]i瞬变。结果 10μmol.L-1 Iso可以诱导心肌细胞肥大,腺苷A1受体激动剂R-PIA可以使其蛋白含量降低、ANP的mRNA表达减少、CaN相对表达降低、[Ca2+]i荧光强度减小,CSA、RP-cAMPS有类似抑制作用,PTX预处理的情况下,R-PIA对Iso诱导的心肌肥大的抑制作用消失。结论腺苷A1受体可以通过钙调磷酸酶通路抑制Iso诱导的心肌肥大,其机制与降低细胞内[Ca2+]i浓度及CaN表达有关。
Aim To observe the inhibitory effect of adenosine A1 receptor stimulation on calcineurin（CaN） signal pathways on isoproterenol-induced cardiomyocyte hypertrophy in vitro cultured myocardial cells from neonatal rats.Methods Myocardial cells of neonatal rats were cultured in vitro.The hypertrophic myocytes were induced by Iso 10 μmol.L-1 before adenosine A1 receptor agonist R-PIA 1 μmol.L-1 was administered.The antihypertrophic effect of adenosine A1 receptor stimulation was observed in the presence of ciclosporine A（CsA） 1 μmol.L-1,cAMP triethyl-ammonium salt（Rp-cAMPS） 1 μmol.L-1,and pertussistoxin（PTX） 5 mg.L-1.The total protein content was assayed by the method of Lowry.The expression of mRNA of atrial natriuretic peptide（ANP） was determined by RT-PCR.[Ca2＋]i was measured by confocal microscope using Fluo-3 / AM as flouresecent indicator.The relative expression of CaN was determined by Western blot.Results Compared with normal control group,10 μmol.L-1 Iso could induce cardiomyocyte hypertrophy.Compared with Iso model group,1 μmol.L-1 R-PIA could obviously inhibit Iso-induced increase of the protein content,cardiomyocyte volume and expression of CaN,and calciumion fluorescence intensity,which was similar to CsA and Rp-cAMPS.But the inhibitory effects of R-PIA were lost when preincubated with PTX.Conclusion Adenosine A1 receptor can inhibit cardiomyocyte hypertrophy induced by Iso through decreasing CaN signal pathways and Ca2＋.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2012年第6期847-852,共6页
Chinese Pharmacological Bulletin
基金
辽宁省教育厅团队项目(No 2009T064)
辽宁省科技厅科技计划项目(No 2009225010-40)
