Cardiac contractile function during coronary stenosis in dogs:
association of adenosine in glycolytic dependence.
Fang, H. Kenith, Cord Sturgeon, Laurence J. Segil, Richard L. Ripper,
and William R. Law.
Research, Surgery, & Anesthesiology Services, West Side
Veterans Administration Medical Center, Chicago, IL, and Departments
of Surgery, Anesthesiology and Physiology & Biophysics,
University of Illinois at Chicago, College of Medicine, Chicago, IL
60612
APStracts 3:0501H, 1996.
We tested the hypothesis that during critical coronary stenosis,
endogenous adenosine alters myocardial glucose utilization to support
myocardial contractile function (MCF). Anesthetized mongrel dogs were
instrumented to measure hemodynamic variables, regional MCF
(sonomicrometry), and substrate uptakes. Critical coronary artery
stenosis was established with a screw clamp on the Cx artery. Either
8-phenyltheophylline (8-PTH, 3x10-7 moles/min; adenosine receptor
blockade), iodoacetate (IODO, 1x10-5 mole/min; glycolysis blockade),
or vehicle were infused into the Cx and LAD arteries. Critical
coronary stenosis caused small decreases in arterial blood pressure
and Cx blood flow, but no significant changes in MCF or other
hemodynamics. There was a significant decrease in O2
supply/consumption ratio in the stenotic region, and increased
glucose uptake. Infusion of either 8-PTH or iodoacetate caused a
decrease in MCF in the stenotic Cx region concomitant with decreased
glucose uptake, and without further changes in blood flows. This was
not seen in the non-stenotic (LAD) region. These data support the
hypothesis, indicating that glycolysis is vital for maintaining
regional MCF during a decrease in the myocardial O2 supply to
consumption ratio, and that adenosine is important in this regard
independent of its vasoactive properties.
Received 18 June 1996; accepted in final form 20 November 1996.
APS Manuscript Number H539-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996