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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The effects of epinine or dopamine (both 1-10 micrograms kg-1 min-1) on systemic haemodynamics and plasma concentrations of catecholamines and prolactin were studied in conscious pigs before and after combined non-selective alpha- and beta-adrenoceptor blockade. 2. The plasma concentrations of the two compounds did not differ from each other over the entire dose-range. 3. Epinine increased aortic blood flow (AoBF, 24 +/- 6%), which was due to an increase in heart rate (HR) for doses less than 10 micrograms kg-1 min-1. At 10 micrograms kg-1 min-1, HR decreased slightly (10 +/- 3%, as compared to the value obtained at 5 micrograms kg-1 min-1) and stroke volume increased up to 15% (P < 0.05). Mean arterial pressure (MAP, 99 +/- 3 mmHg at baseline) decreased dose-dependently (14 +/- 2%, P < 0.05) up to the infusion rate of 5 micrograms kg-1 min-1, but increased by 4.0 +/- 1.8 mmHg during infusion of 10 micrograms kg-1 min-1. Systemic vascular resistance (SVR) decreased up to 23 +/- 3% for doses less than 10 micrograms kg-1 min-1, but did not change further during infusion of the highest dose. LVdP/dtmax increased during the two highest infusion rates up to 22 +/- 6% (P < 0.05). After the infusion was stopped there was an abrupt increase in HR (18 +/- 4%, P < 0.05) and a further decrease in SVR before all parameters returned to baseline.4. Dopamine caused increases in AoBF (27 +/- 3%) similar to epinine, the only difference being that HR continued to increase (32 +/- 5%) and MAP (13 +/- 3%) and SVR continued to decrease (31 +/- 3%) over the entire dose-range. The increase in LVdP/dt,,,, at the highest dose (48 +/- 4%, P <0.05) was more pronounced than with epinine.5. Adrenoceptor blockade inhibited all epinine-induced changes, but did not affect the dopamineinduced changes in AoBF, SVR and MAP, but attenuated the increases in HR and LVdP/dtmax.6. Noradrenaline (NA) and adrenaline (Ad) concentrations did not change during infusion of epinine or dopamine, but NA increased by 50% within 2.5 min after stopping the infusion of epinine. After adrenoceptor blockade NA and Ad concentrations did not change during infusion of dopamine, which contrasted with a decrease of 55 +/- 5% (P<0.05) in NA during infusion of epinine.7. Prolactin concentrations decreased gradually from 480 +/- 40 pg ml-' to 270 +/- 50 pg ml1' (P<0.05) during infusion of epinine, but did not change significantly during dopamine infusion.8. The differential effects of epinine and dopamine on MAP, SVR, plasma NA (before and after adrenoceptor blockade) and prolactin, leads us to conclude that in conscious pigs, epinine is a more potent a, P2 and D2-receptor agonist, but a weaker D,-receptor agonist than dopamine.
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PMID:Differential cardiovascular and neuroendocrine effects of epinine and dopamine in conscious pigs before and after adrenoceptor blockade. 133 Jan 72

Intravenous (i.v.) infusions (1, 2.5, 5, and 10 micrograms/kg/min for 10 min) were used to evaluate the cardiovascular effects of epinine (N-methyl-dopamine) in 8 conscious pigs. Epinine is a nonselective and nonspecific dopamine (DA) agonist, that also stimulates alpha- and beta-adrenoceptors. Epinine (1-5 microgram/kg/min) increased cardiac output (CO) by up to 15 +/- 5% (p less than 0.05), owing to an increase in heart rate (HR, 24 +/- 6%), but an increase in stroke volume (SV, 16 +/- 4%) caused the further increase in CO at 10 micrograms/kg/min. Mean arterial blood pressure decreased gradually from 100 +/- 5 mm Hg to 84 +/- 4 mm Hg during infusions up to 5 microgram/kg/min, but increased to 89 +/- 4 mm Hg during infusion of 10 micrograms/kg/min (p less than 0.05). Systemic vascular resistance had decreased from 36.5 +/- 2.8 to 27.5 +/- 3.0 mm Hg/L/min after infusion of 5 micrograms/kg/min but did not change further during infusion of 10 micrograms/kg/min. LV dP/dtmax increased only at 10 micrograms/kg/min. Myocardial blood flow did not change at any dose, owing to metabolically regulated coronary vasodilatation (myocardial work did not change). Flow to the adrenals (up to 110 +/- 37%) and the spleen (up to 95 +/- 13%) increased dose dependently. Cerebral blood flow increased only at the highest dose (15 +/- 5%, p less than 0.05); flow to the kidneys, liver, small intestine, and skeletal muscle did not change. Flow decreased to the stomach (21 +/- 5%) and skin (for doses less than 2.5 micrograms/kg/min).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of epinine on systemic hemodynamics and regional blood flow in conscious pigs. 138 Jun 1

Ibopamine is an orally active derivative of dopamine (DA) which metabolizes to its active form, epinine. Epinine is one of the few catecholamines that possess dopaminergic--DA1 and DA2--activity, alpha 1, alpha 2, beta 1, and beta 2 activity, with indirect sympathomimetic action of dopamine. Ibopamine increased positive dP/dt, stroke volume, aortic blood flow, renal blood flow, and diuresis in animals. In healthy volunteers and patients with heart failure, a single oral dose of ibopamine showed primary vasodilating action (postsynaptic DA1 activity and presynaptic DA2 activity). Following a single oral dose of 100 or 200 mg of ibopamine, the plasma concentration of epinine reached its peak within 30 minutes, and declined rapidly so that concentration was not detectable after 1.5-3 hours. Pharmacokinetics and hemodynamic effects in congestive heart failure patients are also discussed.
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PMID:Clinical pharmacology of ibopamine. 167 50

The effects of intraduodenal ibopamine (a new orally active inotropic agent claimed to have haemodynamic effects similar to dopamine) on isovolumic relaxation were monitored for 90 min in eight closed-chest anaesthetized dogs. Dopamine and epinine (ibopamine active metabolite) were also infused at graded doses. After 15 min, ibopamine (12 mg/kg) shortened the time constant of isovolumic relaxation, and increased stroke volume and mean aortic pressure. Peak positive dP/dt increased significantly only 10 min later. Heart rate did not change. Dopamine (10 micrograms/kg per min) similarly reduced the time constant, and increased stroke volume, mean aortic pressure, peak positive dP/dt and heart rate. Epinine (10 micrograms/kg per min) caused similar changes in peak positive dP/dt, stroke volume, mean aortic pressure, and accelerated time constant without raising the heart rate. Ibopamine and epinine therefore significantly improved the isovolumic relaxation phase, like dopamine, without however affecting the heart rate.
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PMID:Acute haemodynamic effects of ibopamine and dopamine on isovolumic relaxation. 276 16