ISSN:
1432-1912
Keywords:
N,N-di-n-propyldopamine
;
Dopamine receptors
;
Hypotension
;
Bradycardia
;
Propranolol
;
Nitroglycerin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Intravenous infusion of N,N-di-n-propyldopamine (DPDA) (100–900 μg/kg) produced dose-related arterial hypotension which was accompanied by bradycardia at higher doses. Increments in arterial blood pressure induced by carotid artery occlusion were attenuated during administration of DPDA (600 μg/kg, i.v.), whereas cardiovascular compensation to postural change remained unaltered. DPDA-induced hypotension and its attenuation of carotid occlusion responses were prevented by pretreatment with sulpiride (0.5 mg/kg, i.v.), indicating involvement of dopamine receptors in these activities. Hemodynamic studies demonstrated that DPDA (600 μg/kg, i.v.) lowered mean arterial blood pressure by dilating the systemic vasculature; mean aortic blood flow increased in the presence of bradycardia due to an increment in stroke volume. Left ventricular minute work, stroke work and myocardial oxygen consumption were decreased as a consequence of the hypotension and bradycardia produced by DPDA. The results of other experiments illustrated that propranolol (0.5 mg/kg, i.v.) and nitroglycerin (40 μg/kg, i.v.) administered in combination, but not individually, resulted in hemodynamic alterations similar to those of DPDA (600 μg/kg, i.v.). However, at equivalent reductions in mean arterial blood pressure, cardiac rate and myocardial oxygen consumption only DPDA increased mean aortic blood flow and lowered left ventricular end-diastolic pressure. The hemodynamic effects produced by DPDA are interpreted to be a reflection of its known ability to inhibit neurogenic release of noradrenaline by stimulation of neuronal dopamine receptors. The composite data suggest that orally effective dopamine receptor agonists may have clinical utility as antihypertensive agents with minimal liability for producing orthostasis. Furthermore, a potential use in ischemic heart disease is suggested by data indicating that DPDA maintained systemic perfusion at reduced levels of myocardial work and oxygen consumption.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00586351
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