Measurement of regional myocardial blood flow in rats by unlabeled
microspheres and coulter channelyzer.
Wang, Xuejun, Faqian Li, Suleman Said, Joseph M. Capasso, and A.
Martin Gerdes.
Department of Anatomy and Structural Biology, University of South
Dakota School of Medicine, Vermillion, South Dakota 57069-2390
APStracts 3:0101H, 1996.
A relatively inexpensive, expeditious, new nonradioactive microsphere
method for measuring regional myocardial blood flow (RMBF) was
developed with unlabeled microspheres and a Coulter Channelyzer. To
validate the efficiency of this method, hearts from rats were
perfused ex vivo by retrograde aortic cannulation. Unlabeled
microspheres of varying size were injected into a side arm in the
aortic cannula, or added to blood samples collected from the rats.
Microspheres were then recovered from the cardiac tissue and blood
samples. It was found that over 97% of perfused microspheres
(diameter >9.4 [mu]m) were retained in the myocardium and 94.8
+/- 2.2% of the trapped microspheres were recovered and counted
successfully using a Counter Channelyzer. The percent recovery of
microspheres from 2- and 0.5-ml blood samples were 95.4 +/- 2.3% and
95.3 +/- 3.1%, respectively. Blood flow to the anterior and posterior
halves of the ventricular free walls and septum were measured in 6
rats; excellent agreements were found between the results yielded by
10-, 15-, and 20-[mu]m unlabeled microspheres injected
simultaneously. The transmural flow gradients in left ventricular
free wall estimated by 10- and 15-[mu]m spheres did not significantly
differ from each other. Thus, the method developed here provides a
new alternative for measurement of RMBF which currently allows at
least three measurements for non-transmural-gradient RMBF, and at
least two measurements for transmural gradient RMBF.
Received 13 December 1995; accepted in final form 21 February
1996.
APS Manuscript Number H1156-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96