The involvement of desipramine-sensitive processes in the extraction of various catecholamines from plasma in the anaesthetized rabbit.

Abstract

The effects of desipramine on the total body plasma clearance (Cl) as well as the systemic fractional extraction (ERs) of noradrenaline, dopamine, adrenaline, and isoprenaline, and on the pulmonary fractional extraction (ERp) of dopamine and adrenaline were determined in the anaesthetized rabbit. Under control conditions, noradrenaline, dopamine, adrenaline, and isoprenaline had Cl values of 59.5, 116.2, 68.0, 78.4 (ml kg-1 min-1) and ERs values of 0.709, 0.789, 0.694, 0.669, respectively. The ERp of dopamine was 0.235, while that of adrenaline did not differ from zero. Desipramine reduced the Cl of noradrenaline (by 20%), but did not affect that of the other amines. It also reduced the ERs of noradrenaline (by 31%), dopamine (by 10%) and adrenaline (by 10%); the ERp of dopamine was diminished by 84%.