Journal of Applied Physiology, Vol 39, Issue 6 1043-1047, Copyright © 1975 by American Physiological Society
Functional evaluation of the rat heart in situ
R. T. Dowell, A. F. Cutilletta and P. C. Sodt
We have developed methods for evaluating muscle function in the intact rat
heart in situ using a contractility index (dP/dt)P-1, calculated from left
ventricular pressure derivative-left ventricular pressure loop plots.
Aortic flow measurements were also taken to further characterize in situ
rat heart function. The preparation remained functionally stable and was
within physiological blood gas and pH limits for at least 30 min following
surgical procedures. The contractility index was not influenced by
increased afterload, decreased preload or increased heart rate; however,
appropriate changes were observed following isoproterenol and propranolol
administration. Appropriate changes in aortic flow measurements were
observed also with the above interventions. These studies demonstrate that
the in situ rat heart is a stable physiological experimental preparation.
It should be useful for evaluating heart function since a contractility
index derived from pressure-velocity relationships and measurements
necessary for pump function analysis can be obtained simultaneously.
