The isolated perfused rat heart: a model for studying myocardial hypoxia or ischaemia

The aim of this paper is to consider the advantages of using isolated heart preparations in studies designed to investigate the effect of hypoxia or ischaemia on myocardial cells. After a brief description of the two most frequently used experimental models of perfused hearts, namely the Langendorff preparation and the working heart preparation, some of the various methods used to induce hypoxia or ischaemia are described, as well as some of the possible techniques allowing to assess metabolic alterations occurring in these pathological situations. After discussing the limitations and advantages specific to the Langendorff and working heart preparations, the suitability of isolated heart models in studies on myocardial protection is then considered. To illustrate this point, the effect of intravenous administration of the slow calcium channel blocker bepridil (5 mg X kg-1) on post-ischaemic recovery of cardiac function and metabolism after global normothermic ischaemia of the isolated heart is reported. It is concluded that isolated heart preparations allow a fine control of experimental conditions with the advantage that functional and metabolic measurements can be easily made.