EFFECTS OF ARTIFICIAL BLOOD (FC-43 EMULSION) ON MYOCARDIAL ENERGY-METABOLISM IN THE RAT HEART-LUNG PREPARATION

We have assessed the effects of artificial blood (FC-43 emulsion) on m yocardial energy metabolism in the rat heart-lung preparation. Animals were allocated to four groups (n = 8 each group) according to the rat io of perfusion blood and FC-43 as follows: group 1 = control, perfusi on blood only; group 2 = 50% FC-43; group 3 = 75% FC-43; and group 4 = 100% FC-43. Hearts were perfused initially to a cardiac output of 30 ml min(-1) and mean arterial pressure of 50 mm Hg. Thirty minutes afte r perfusion, the hearts were freeze-dried for 6 days. Myocardial high energy phosphates (ATP, ADP and AMP) were measured by high pressure li quid chromatography. Myocardial lactate and glycogen concentrations we re measured by enzymatic methods. There were almost no significant dif ferences in cardiac output, systolic pressure, right atrial pressure a nd heart rate among the groups. Oxygen contents of the perfusate in al l FC-43 groups were significantly lower than those in the control grou p. Myocardial ATP concentrations in vats receiving 50%, 75% and 100% F C-43 were significantly lower than those in the control group. In addi tion, myocardial ADP and AMP concentrations in rats receiving 75% and 100% FC-43 were significantly higher than those in the control group. Although there is adequate oxygen-carrying capacity in FC-43 to mainta in cardiac function during perfusion, the energy levels in the hearts perfused with FC-43 were lower than those in normal hearts.