Fassina Lorenzo, Di Grazia Antonio, Naro Fabio, Monaco Lucia, De Angelis Maria Gabriella Cusella, Magenes Giovanni
Department of Systems and Computer Science, University of Pavia, Pavia, Italy.
Int J Artif Organs. 2011 Jul;34(7):546-58. doi: 10.5301/IJAO.2011.8510.
Many important observations and discoveries in heart physiology have been made possible using the isolated heart method of Langendorff. Nevertheless, the Langendorff method has some limitations and disadvantages such as the vulnerability of the excised heart to contusions and injuries, the probability of preconditioning during instrumentation, the possibility of inducing tissue edema, and high oxidative stress, leading to the deterioration of the contractile function. To avoid these drawbacks associated with the use of a whole heart, we alternatively used beating mouse cardiac syncytia cultured in vitro in order to assess possible ergotropic, chronotropic, and inotropic effects of drugs. To achieve this aim, we developed a method based on image processing analysis to evaluate the kinematics and the dynamics of the drug-stimulated beating syncytia starting from the video recording of their contraction movement. In this manner, in comparison with the physiological no-drug condition, we observed progressive positive ergotropic, positive chronotropic, and positive inotropic effects of 10 µM isoproterenol (ß-adrenergic agonist) and early positive ergotropic, negative chronotropic, and positive inotropic effects of 10 µM phenylephrine (alpha-adrenergic agonist), followed by a late phase with negative ergotropic, positive chronotropic, and negative inotropic trends. Our method permitted a systematic study of in vitro beating syncytia, producing results consistent with previous works. Consequently, it could be used in in vitro studies of beating cardiac patches, as an alternative to Langendorff's heart in biochemical and pharmacological studies, and especially when the Langendorff technique is inapplicable (e.g., in studies about human cardiac syncytium in physiological and pathological conditions, patient-tailored therapeutics, and syncytium models derived from induced pluripotent/embryonic stem cells with genetic mutations). Furthermore, the method could be helpful in heart tissue engineering and bioartificial heart research to "engineer the heart piece by piece." In particular, the proposed method could be useful in the identification of a suitable cell source, in the development and testing of "smart" biomaterials, and in the design and use of novel bioreactors and microperfusion systems.
利用兰根多夫离体心脏法，人们在心脏生理学领域取得了许多重要的观察结果和发现。然而，兰根多夫法存在一些局限性和缺点，比如离体心脏易受挫伤和损伤，在仪器操作过程中存在预处理的可能性，可能会诱发组织水肿以及产生高氧化应激，进而导致收缩功能恶化。为避免使用完整心脏带来的这些缺点，我们转而使用体外培养的搏动小鼠心肌细胞团，以评估药物可能产生的变力性、变时性和变传导性效应。为实现这一目标，我们开发了一种基于图像处理分析的方法，从药物刺激搏动心肌细胞团收缩运动的视频记录开始，评估其运动学和动力学。通过这种方式，与生理无药状态相比，我们观察到10 μM异丙肾上腺素（β肾上腺素能激动剂）具有逐渐增强的正性变力性、正性变时性和正性变传导性效应，而10 μM去氧肾上腺素（α肾上腺素能激动剂）则具有早期正性变力性、负性变时性和正性变传导性效应，随后是晚期负性变力性、正性变时性和负性变传导性趋势。我们的方法允许对体外搏动心肌细胞团进行系统研究，所得结果与先前的研究一致。因此，它可用于搏动心脏组织块的体外研究，在生化和药理学研究中作为兰根多夫心脏的替代方法，特别是当兰根多夫技术不适用时（例如，在生理和病理条件下关于人类心肌细胞团、患者个体化治疗以及源自诱导多能/胚胎干细胞且带有基因突变的心肌细胞团模型的研究）。此外，该方法有助于心脏组织工程和生物人工心脏研究中“逐块构建心脏”。特别是，所提出的方法可用于识别合适的细胞来源、开发和测试“智能”生物材料以及设计和使用新型生物反应器和微灌注系统。
