[Thermodynamic analysis of oxygen/transport to the turtle heart]

Isolated turtle hearts were perfused, at constant flow, with human erytrocytes suspensions containing different levels of 2,3-DPG. PO2 measurements, in the blood leaving the heart, resulted in lower figures when the tissue was perfused with low affinity blood compared with perfusion of high affinity blood. Thermodynamic analysis was, also, carried out at four different levels of temperature. The results suggest that, in severe hypoxia, oxygen delivery to the tissue is increased when perfusion is performed with high oxygen affinity blood.