Bussek Alexandra, Wettwer Erich, Christ Torsten, Lohmann Horst, Camelliti Patrizia, Ravens Ursula
Department of Pharmacology and Toxicology, University of Technology, Dresden, Germany.
Cell Physiol Biochem. 2009;24(5-6):527-36. doi: 10.1159/000257528. Epub 2009 Nov 4.
Isolated papillary muscles and enzymatically dissociated myocytes of guinea-pig hearts are routinely used for experimental cardiac research. The aim of our study is to investigate adult mammalian ventricular slices as an alternative preparation.
Vibratome cut ventricular slices (350 microm thick) were examined histologically and with 2-photon microscopy for fibre orientation. Intracellular action potentials were recorded with conventional glass microelectrodes, extracellular potentials were measured with tungsten platinum electrodes and multi-electrode arrays (MEA).
Dominant direction of fibre orientation was absent in vertical and horizontal transmural slices, but was longitudinal in tangential slices. Control action potential duration (APD(90), 169.9 +/- 4 ms) and drug effects on this parameter were similar to papillary muscles. The L-type Ca-channel blocker nifedipine shortened APD(90) with a half maximal effective concentration (EC(50)) of 4.5 microM. The I(Kr) blocker E4031 and neuroleptic drug risperidone prolonged APD(90) with EC(50) values of 31 nM and 0.67 microM, respectively. Mapping field potentials on multi-electrode arrays showed uniform spread of excitation with a mean conduction velocity of 0.47 m s(-1).
Slices from adult mammalian hearts could become a useful routine model for electrophysiological and pharmacological research.
豚鼠心脏的分离乳头肌和酶解心肌细胞常用于心脏实验研究。本研究旨在探讨成年哺乳动物心室切片作为一种替代制备方法。
用振动切片机切取心室切片（350微米厚），进行组织学检查并用双光子显微镜观察纤维方向。用传统玻璃微电极记录细胞内动作电位，用钨铂电极和多电极阵列（MEA）测量细胞外电位。
垂直和水平透壁切片中不存在纤维方向的主导方向，但在切线切片中为纵向。对照动作电位时程（APD(90)，169.9±4毫秒）及药物对该参数的影响与乳头肌相似。L型钙通道阻滞剂硝苯地平使APD(90)缩短，半数最大效应浓度（EC(50)）为4.5微摩尔。I(Kr)阻滞剂E4031和抗精神病药物利培酮使APD(90)延长，EC(50)值分别为31纳摩尔和0.67微摩尔。在多电极阵列上绘制场电位显示兴奋均匀传播，平均传导速度为0.47米/秒。
成年哺乳动物心脏切片可能成为电生理和药理研究的有用常规模型。
