A paracorporeal rat heart model for ischemic and reperfusion studies

Paracorporeal rat hearts were supplied with blood derived from the abdominal aorta of a supporting rat. The circulatory stability and working capacity of the supporting animal was analyzed in the experimental situation in terms of PO2, SO2, PCO2, HCO3, pH and electrolytes, all of which were within the normal range before and during a 60 min period of paracorporeal perfusion. For evaluation of ischemic damage in this model studies were made on three groups of excised hearts. They were subjected to 10, 15 or 20 min of complete global ischemia at 37 degrees C (ambient temperature) and reperfused for 30 min, including ECG, observations of contractility and an analysis of creatine kinase efflux in the coronary effluent. The results showed good reproducibility and the data were in accordance with reports from similar studies on Langendorff preparations. The model, which is easily set up, inexpensive and based upon pulsatile blood perfusion, should be more physiologic than the conventional Langendorff preparation.