Effects of morphine on catecholamine release and arrhythmias evoked by myocardial ischaemia in rats.
Br J Pharmacol
; 90(1): 247-54, 1987 Jan.
Article
em En
| MEDLINE
| ID: mdl-3814921
ABSTRACT
The effects of morphine (10 mg kg-1 i.p.) on haemodynamics, arrhythmias and plasma and myocardial catecholamines (CA) were studied after coronary artery occlusion in anaesthetized rats. Myocardial intraneuronal CA were assessed histofluorimetrically and CA concentrations measured by high performance liquid chromatography. Morphine increased blood pressure, presumably due to higher plasma noradrenaline (NA) concentrations found in morphine-treated rats. Morphine increased the area of catecholamine-containing fluorescing neurones in the myocardium (as a percentage of total field area) 60 min after sham-operation (0.87 +/- 0.07%) or occlusion (0.57 +/- 0.05%) compared to untreated animals (0.67 +/- 0.06 and 0.38 +/- 0.03% respectively). Tissue NA content was not significantly affected by coronary occlusion and/or morphine within the first 60 min. Morphine had no effect on ischaemia-induced arrhythmias. Whether the higher intraneuronal NA content following morphine resulted from reduced central sympathetic outflow to the heart, presynaptic inhibition of NA release, or increased uptake due to higher plasma concentrations is unclear. Ischaemia-induced local NA release appears independent of these mechanisms, as it was unaffected by morphine.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
/
Catecolaminas
/
Doença das Coronárias
/
Morfina
/
Miocárdio
Tipo de estudo:
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
Br J Pharmacol
Ano de publicação:
1987
Tipo de documento:
Article