[The mechanism of the natriuretic action of dopamine in the anesthetized dogs (author's transl)].
1. The natriuretic effect of increasing doses of dopamine (1.5 to 15 x 10(-8) moles/kg/min intrarenally) was compared in dogs (pentobarbital anesthetized) who were either water restricted or overhydrated. 2. The dopaminergic response to doses larger than 1.5 x 10(-8) moles/kg/min (3 micrograms) was hidden either by important alpha-adrenergic effects or by renal reaction to the modifications in systemic haemodynamics. 3. Renal blood flow was increased by a dose of 1.5 x 10(-8) moles/kg/min of dopamine. At the same dose, natriuresis was increased only in hydrated dogs. Glomerular filtration rate only increased in water restricted animals. 4. The natriuretic effect of dopamine depended on the catecholamine induced variations of renal haemodynamic. 5. In water restricted animals, the absence of natriuretic effect of dopamine goes in hand with an absence of variation in filtration fraction. 6. In hydrated animals, the dopamine-induced natriuretic effect, in the absence of increased glomerular filtration, is tied to a decreased proximal tubular reabsorption of sodium probably secondary to the haemodynamic effects of this catecholamine.
D000758:Anesthesia; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D004285:Dogs; D004298:Dopamine / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects; D007668:Kidney / Q000098:blood supply; D007684:Kidney Tubules / Q000378:metabolism; D009318:Natriuresis / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects; D014868:Water Deprivation
D002395:Catecholamines; D004298:Dopamine
Mécanisme de l'action natriurétique de la dopamine chez le chien anesthésie.