A simplified alloperfused rat heart model for studying myocardial protection

Isolated hearts are widely used to study myocardial protection because they allow for rigorous control of parameters that is not readily achievable by the in-vivo heart models. The classic Langendorff system and its modifications using asanguinous perfusates have an obvious limitation in that asanguinous reperfusion is clinically irrelevant. The available blood-perfused heart systems are complicated by the use of pumping circuits. In this study, an isolated rat heart, harvested under cold cardioplegia, is alloperfused with the blood coming from an isogenic support rat. The coronary effluent returns to the support rat by gravity. The model was validated by testing its response to normothermic ischemia and reperfusion, and the expected protective effects of hypothermic-cardioplegia are demonstrated. A marked difference in response to ischemia is shown between this model and the buffer-perfused heart. We conclude that alloperfused isolated rat heart model is an inexpensive and more clinically relevant method of screening various new modes of myocardial protection.