Role of nitric oxide in systemic hemodynamic responses to dobutamine, epinephrine, and amrinone.
OBJECTIVE
This study was designed to investigate the extent to which the systemic vasodilator effects of dobutamine, epinephrine, and amrinone are modulated by the endothelium-derived relaxing factor, nitric oxide (NO).


METHODS
This was a prospective study of low and high doses of the agonists before and after inhibition of NO synthesis.


METHODS
Experiments were performed in the basic research laboratories of the Center for Anesthesiology Research.


METHODS
Pentobarbital-anesthetized, intact Sprague-Dawley rats were studied in seven separate groups of eight rats each.


METHODS
The systemic vasodilator responses to the agonists were assessed before and after the administration of the NO synthase inhibitor, NG-nitro-L-arginine methyl ester.


RESULTS
Decreases in systemic vascular resistance in response to dobutamine and epinephrine were not observed after inhibition of NO synthesis, whereas the decrease in systemic vascular resistance in response to amrinone was still apparent.


CONCLUSIONS
The results suggest that dobutamine and epinephrine produce systemic vasodilation through the release of NO, whereas amrinone produces vasodilation independent of NO release.
Hemida
M R
MR
Center for Anesthesiology Research, Cleveland Clinic Foundation, OH 44195, USA.
Brum
J M
JM
Estafanous
F G
FG
Khairallah
P A
PA
Shamloula
M
M
El-Kasstawy
B
B
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004280:Dobutamine / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011446:Prospective Studies; D051381:Rats; D017207:Rats, Sprague-Dawley; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*
D000318:Adrenergic beta-Agonists; D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D009569:Nitric Oxide; D004280:Dobutamine; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester; D004837:Epinephrine