TY - JOUR
T1 - Direct in vivo effects of nitric oxide on the coronary circulation
AU - Chambers, Jeffrey W.
AU - Voss, Gregory S.
AU - Snider, Jason R.
AU - Meyer, Susan M.
AU - Cartland, Julie L.
AU - Wilson, Robert F.
PY - 1996/10
Y1 - 1996/10
N2 - To determine the direct in vivo effects of nitric oxide (NO) on the coronary circulation, we infused NO-saturated saline (1.0 ± 0.1 mmol/l) into the coronary arteries of anesthetized dogs and measured changes in coronary blood flow velocity (CBFV) with a Doppler catheter, changes in coronary artery size with quantitative angiography, and transmural myocardial perfusion with radioactive microspheres. Boluses of NO (1-8 μmol) caused a stepwise increase in CBFV (3.1 ± 0.3 × basal CBFV at 8 μmol) similar to that caused by adenosine (2.6 ± 0.3 × basal CBFV, maximal dose). Continuous subselective infusions (0.1, 1.0, and 4.0 μmol/min) caused dose-dependent increases in CBFV (2.2 ± 0.3 × basal CBFV at 4.0 μmol/min) and in epicardial artery diameter (+15 ± 6% diam). Left main infusions (8 μmol/min) caused a stepwise increase in CBFV and in the endocardial-to-epicardial flow ratio without affecting systemic hemodynamics. Brief infusion of NO (2 min) did not significantly reduce acetylcholine-mediated endothelial NO release. Therefore, despite rapid metabolism, direct intraarterial infusion of NO can be given at a rate sufficient to overwhelm metabolic elimination, providing direct evidence that NO is a potent in vivo coronary vasodilator. Moreover, the enhanced subendocardial vasodilator response to direct NO infusion suggests increased regional sensitivity to NO.
AB - To determine the direct in vivo effects of nitric oxide (NO) on the coronary circulation, we infused NO-saturated saline (1.0 ± 0.1 mmol/l) into the coronary arteries of anesthetized dogs and measured changes in coronary blood flow velocity (CBFV) with a Doppler catheter, changes in coronary artery size with quantitative angiography, and transmural myocardial perfusion with radioactive microspheres. Boluses of NO (1-8 μmol) caused a stepwise increase in CBFV (3.1 ± 0.3 × basal CBFV at 8 μmol) similar to that caused by adenosine (2.6 ± 0.3 × basal CBFV, maximal dose). Continuous subselective infusions (0.1, 1.0, and 4.0 μmol/min) caused dose-dependent increases in CBFV (2.2 ± 0.3 × basal CBFV at 4.0 μmol/min) and in epicardial artery diameter (+15 ± 6% diam). Left main infusions (8 μmol/min) caused a stepwise increase in CBFV and in the endocardial-to-epicardial flow ratio without affecting systemic hemodynamics. Brief infusion of NO (2 min) did not significantly reduce acetylcholine-mediated endothelial NO release. Therefore, despite rapid metabolism, direct intraarterial infusion of NO can be given at a rate sufficient to overwhelm metabolic elimination, providing direct evidence that NO is a potent in vivo coronary vasodilator. Moreover, the enhanced subendocardial vasodilator response to direct NO infusion suggests increased regional sensitivity to NO.
KW - Artery size
KW - Coronary blood flow velocity
KW - Endothelium-mediated vasodilation
KW - Transmural myocardial perfusion
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U2 - 10.1152/ajpheart.1996.271.4.h1584
DO - 10.1152/ajpheart.1996.271.4.h1584
M3 - Article
C2 - 8897955
AN - SCOPUS:33750817121
SN - 0363-6135
VL - 271
SP - H1584-H1593
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 4
ER -