腺苷A1受体与к阿片肽受体激活对异丙肾上腺素诱导的心肌细胞肥大的交互作用

Cross-talk between adenosine A1 receptor and κ-opioid receptor activation on isoproterenol-induced cardiomyocyte hypertrophy

目的观察腺苷A1受体与κ阿片肽受体(κ-OR)激活对异丙肾上腺素(Iso)诱导的心肌细胞肥大的交互作用及机制。方法体外培养大鼠乳鼠心肌细胞,以Iso 10μmol/L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和κ-OR激动剂U50,488H1μmol/L对其作用,进一步探讨腺苷A1受体拮抗剂8-cyclopentyl-1,3-dipropylxanthine(CPDPX)0.1μmol/L存在时κ-OR的激活对细胞肥大的影响和κ-OR拮抗剂nor-binaltorphimine(NOR-BNI)1μmol/L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;消化分离法及计算机图像分析系统测细胞体积;以Fluo-3/AM为荧光探针,共聚焦显微镜下测量心肌细胞内[Ca2+]i变化;RT-PCR法检测心肌细胞心房钠尿肽(ANP)的mRNA表达。结果 10μmol/LIso可以诱导心肌细胞肥大,1μmol/L的R-PIA(腺苷A1受体激动剂)可以明显抑制Iso诱导的心肌细胞蛋白合成增加、体积增大、ANPmRNA表达增加、心肌细胞内[Ca2+]i荧光强度增大,该抑制作用可以被1μmol/Lκ-OR拮抗剂NOR-BNI部分阻断;κ-OR激动剂U50,488H1μmol/L可以明显抑制Iso诱导的心肌细胞蛋白合成增加、体积增大、ANPmRNA表达增加、心肌细胞内[Ca2+]i荧光强度增大,该抑制作用可以被腺苷A1受体拮抗剂CPDPX部分阻断。结论腺苷可通过激动A1受体、阿片肽可通过激动κ受体抑制Iso诱导的心肌肥大,二者可以通过影响心肌细胞内[Ca2+]i浓度的增大而交互抑制Iso诱导的心肌肥大。

Objective To observe the cross-talk and mechanism between adenosine A1 receptor and κ-opioid receptor（κ-OR） activation on Isoproterenol（Iso）-induced cardiomyocyte hypertrophy in vitro cultured myocardial cells from neonatal rats. Methods The protein content was assayed by the method of Lowry. The volume of cardiomyocytes was measured by computer photograph analysis system. 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. Results Iso 10 μmol/L could induce cardiomyocyte hypertrophy. The protein content, the volume of cardiomyocytes, the expression of mRNA of ANP and [Ca2＋]i induced by iso could be significantly inhibited by 1 μmol/L R-PIA and 1 μmol/L U50,488H. The inhibitory action of R-PIA and U50,488H could be partly blocked by nor-binaltorphimine（NOR-BNI）（antagonist of kappa-opioid receptor）and 8-eyelopentyl-1,3-dipropylxanthine（CPDPX）（antagonist of adenosine A1 receptor）, respectively. Conclusion Adenosine can inhibit cardiomyocyte hypertrophy induced by Iso through activating adenosine A1 receptor;opioid peptides can inhibit cardiomyocyte hypertrophy induced by Iso through activating κ-opioid receptor. The augmentation of [Ca2＋]i is the cross-talk of them on cardiomyocyte hypertrophy induced by Isoproterenol.