Haemodynamic effects of dopexamine and nitric oxide synthase inhibition in healthy and endotoxaemic sheep.
Chronically instrumented awake healthy sheep (n = 6) received the synthetic catecholamine, dopexamine, during or without a background infusion of the nitric oxide synthase inhibitor. L-nitro-arginine-methylester (L-NAME). Three days later, hypotensive-hyperdynamic circulation was induced and maintained by continuous infusion of Salmonella typhosa endotoxin (10 ng/kg per min). After 24 h of continuous endotoxin infusion, the dopexamine L-NAME protocol was repeated. In healthy and endotoxaemic animals with and without nitric oxide synthase inhibition dopexamine caused the same haemodynamic changes: heart rate and cardiac output increased, mean arterial pressure and systemic vascular resistance decreased. L-NAME infusion induced normalisation of the hypotonic-hyperdynamic circulation in endotoxaemic animals. Dopexamine reduced some adverse effects of L-NAME treatment, like increased pulmonary vascular resistance and decreased oxygen delivery. In conclusion the haemodynamic effects of dopexamine are independent of the amount of nitric oxide production. Dopexamine may attenuate some of the adverse effects of nitric oxide synthase inhibition.
Waurick
R
R
Department of Anaesthesiology and Operative Intensive Care Medicine, Westfälische-Wilhelms-Universität, Münster, Germany.
Bone
H G
HG
Meyer
J
J
Booke
M
M
Meissner
A
A
Prien
T
T
Van Aken
H
H
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D004195:Disease Models, Animal; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019446:Endotoxemia / Q000503:physiopathology*; D004731:Endotoxins; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D007262:Infusions, Intravenous; D008168:Lung / Q000098:blood supply / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D010101:Oxygen Consumption / Q000187:drug effects; D012485:Salmonella typhi; D012756:Sheep; D014665:Vasodilator Agents / Q000494:pharmacology*
D000318:Adrenergic beta-Agonists; D004731:Endotoxins; D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; C046318:dopexamine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester; D004298:Dopamine