AJP - Heart and Circulatory Physiology, Vol 249, Issue 2 285-H292, Copyright © 1985 by American Physiological Society
Crystalloid and perfluorochemical perfusates in an isolated working rabbit heart preparation
J. M. Chemnitius, W. Burger and R. J. Bing
Krebs-Henseleit buffer (KH) and a perfluorochemical (FC-43) were compared
as perfusates in an isolated working rabbit heart preparation. Both
perfusates were oxygenated in an identical manner using an infant bubble
oxygenator. After 60 min of perfusion, no difference could be detected in
the ratio of wet to dry heart weight between KH- and FC-43-perfused hearts
(KH, 6.25 +/- 0.3; FC-43, 5.99 +/- 0.20). Left ventricular systolic
pressure, maximal rate of left ventricular pressure rise, mean aortic
systolic pressure, cardiac output, aortic flow, left ventricular power, and
myocardial O2 consumption (MVO2) were significantly higher in
FC-43-perfused hearts throughout the time of perfusion. However, there were
no differences in resistance to cardiac output and heart rate. In KH- and
FC-43-perfused hearts, MVO2 and left ventricular power were closely
correlated (KH, r = 0.793; FC-43, r = 0.831). Significantly higher coronary
flow of KH-perfused hearts could be attributed to the lower viscosity of KH
(1.05 Pa . s) compared with FC-43 (1.91 Pa . s). Increased O2 extraction
during KH perfusion could not compensate for low O2-carrying capacity of KH
buffer (345 compared with 705 nmol O2 X ml-1 in FC-43 emulsion). A
postischemic increase of coronary flow was observed only in FC-43-perfused
hearts (28%). These results demonstrate a different response of perfused
heart preparations to FC-43 and KH buffer.
