Key result
Treadmill exercise in dogs significantly increased coronary venous plasma ATP concentration from 31.1 to 51.2 nM (P<0.01), which correlated linearly with increased coronary blood flow.
Why the study?
Does treadmill exercise increase coronary venous plasma ATP concentration and correlate with coronary blood flow in dogs?
Does treadmill exercise increase coronary venous plasma ATP concentration and correlate with coronary blood flow in dogs?
Absolute Event Rate: 51.2% vs 31.1%
p-value: p=<0.01
This preclinical study provides evidence supporting the hypothesis that ATP released during exercise acts as a local metabolic factor controlling coronary blood flow.
Supports ATP as exercise-induced coronary vasodilator in dogs; leaves open human translation.
It was previously shown that red blood cells release ATP when blood oxygen tension decreases. ATP acts on microvascular endothelial cells to produce a retrograde conducted vasodilation (presumably via gap junctions) to the upstream arteriole. These observations form the basis for an ATP hypothesis of local metabolic control of coronary blood flow due to vasodilation in microvascular units where myocardial oxygen extraction is high. Dogs (n = 10) were instrumented with catheters in the aorta and coronary sinus, and a flow transducer was placed around the circumflex coronary artery. Arterial and coronary venous plasma ATP concentrations were measured at rest and during three levels of treadmill exercise by using a luciferin-luciferase assay. During exercise, myocardial oxygen consumption increased approximately 3.2-fold, coronary blood flow increased approximately 2.7-fold, and coronary venous oxygen tension decreased from 19 to 12.9 mmHg. Coronary venous plasma ATP concentration increased significantly from 31.1 to 51.2 nM (P < 0.01) during exercise. Coronary blood flow increased linearly with coronary venous ATP concentration (P < 0.01). Coronary venous-arterial plasma ATP concentration difference increased significantly during exercise (P < 0.05). The data support the hypothesis that ATP is one of the factors controlling coronary blood flow during exercise.
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Farias et al. (2004) studied Coronary blood flow regulation (n=10). Treadmill exercise vs. Rest was evaluated on Coronary venous plasma ATP concentration (p=<0.01). Treadmill exercise in dogs significantly increased coronary venous plasma ATP concentration from 31.1 to 51.2 nM (P<0.01), which correlated linearly with increased coronary blood flow.
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