Buffer distribution in isolated perfused rat heart measured by rubidium 86

Abstract

The pattern of distribution of Rb⁸⁶ in sections of the isolated perfused heart was determined as a measure of uniformity of coronary artery flow. Results suggest that coronary flow was uniform after nonrecirculated perfusion for 15 min. Similar results were obtained in hearts perfused for 30 and for 60 min. The distribution of Rb⁸⁶ was comparable in hearts perfused for 30 min with perfusate circulated through either coarse porosity, sintered-glass filters or 5-µ Millipore filters. A nonuniform distribution of isotope was demonstrated with ligation of branches of coronary arteries and with the introduction of air. The results suggest that hearts perfused by recirculation of buffer through coarse porosity, sintered-glass filters have a uniform distribution of perfusate throughout the heart.