[Single cell preparation of the human heart. Technic of dissociation and isolation of myocytes].

This paper describes a procedure of cellular dissociation which allows the isolation of single cells from the human heart while preserving their integrity and physiological function necessary for electrophysiological studies in vitro. During open heart surgery, biopsies were obtained from the right atrium of the beating heart in 16 patients immediately before starting the extracorporeal circulation. The tissue was immediately placed in a cardioplegic solution at 4 degrees, and subsequently in a free-calcium solution at 20 degrees from 20' to 30'. It was then exposed to the proteolytic action of Collagenase type I and Protease type VII (Sigma Chemical Co., St Louis, USA) at 35 degrees for a maximum of 5 hours. The cells were finally transferred into a Tyrode solution at room temperature. With this method we obtained up to 70% of intact human myocytes, 40% of which calcium-tolerant. The subsequent electrophysiological studies performed showed that the cells maintained their morphological and physiological properties.