Zimmer H G
Carl-Ludwig-Institute of Physiology, University of Leipzig, Leipzig, Germany.
Can J Cardiol. 2000 Jan;16(1):61-9.
Carl Ludwig was the first physiologist to systematically study isolated organs (heart, muscle, kidney, liver, lung). In his Leipzig Physiological Institute, the isolated perfused frog heart preparation was established in 1866 by Elias Cyon. This preparation was subsequently subjected to various modifications, and many important observations were made by scientists such as Joseph Coats, Henry Pickering Bowditch, Luigi Luciani, Michael Joseph Rossbach, Hugo Kronecker and Otto Frank. The influence of filling pressure on contraction amplitude, the all-or-none law of the heart, the absolute refractory period, postextrasystolic potentiation, the staircase ('Treppe') phenomenon and the dependence of heart function on oxidative metabolism were discovered. The negative chronotropic and inotropic effects of vagus nerve stimulation were also first documented, and a model to induce arrhythmias was established. The isolated frog heart preparation became a widely used standard model for teaching and for basic cardiovascular research. Sidney Ringer discovered the essential role of calcium ions for heart function. Otto Loewi discovered the chemical transduction mechanism of the vagus with acetylcholine as transmitter. In more recent times, the cyclical changes in cAMP and cGMP that occur during the cardiac cycle were first described in the frog heart by Wollenberger and associates. Thus, the isolated perfused frog heart established and modified in Carl Ludwig's Leipzig Physiological Institute led not only to the discovery of basic phenomena, but also to observations that became the basis for concepts to be developed and elaborated later. Furthermore, the isolated perfused frog heart was the starting point for the development of the isolated mammalian heart in the retrogradely perfused, nonworking mode in the heart-lung modification and in the working heart preparation.
卡尔·路德维希是首位系统研究离体器官（心脏、肌肉、肾脏、肝脏、肺）的生理学家。1866年，埃利亚斯·乔恩在他位于莱比锡的生理研究所建立了离体灌注蛙心标本。该标本随后经历了各种改进，约瑟夫·科茨、亨利·皮克林·鲍迪奇、路易吉·卢恰尼、迈克尔·约瑟夫·罗斯巴赫、雨果·克罗内克和奥托·弗兰克等科学家进行了许多重要观察。发现了充盈压对收缩幅度的影响、心脏的全或无定律、绝对不应期、期外收缩后增强、阶梯现象以及心脏功能对氧化代谢的依赖性。迷走神经刺激的负性变时和变力作用也首次得到记录，并建立了诱导心律失常的模型。离体蛙心标本成为教学和基础心血管研究中广泛使用的标准模型。西德尼·林格发现了钙离子对心脏功能的重要作用。奥托·勒维发现了以乙酰胆碱为递质的迷走神经化学传导机制。近代，沃伦伯格及其同事首次在蛙心中描述了心动周期中发生的环磷酸腺苷（cAMP）和环磷酸鸟苷（cGMP）的周期性变化。因此，在卡尔·路德维希的莱比锡生理研究所建立并改进的离体灌注蛙心不仅促成了基本现象的发现，还为后来发展和完善的概念提供了观察基础。此外，离体灌注蛙心是在心肺改良的逆行灌注、非工作模式以及工作心脏标本中发展离体哺乳动物心脏的起点。
