The effects of ageing on neuronal uptake of noradrenaline in the rat

Abstract

We have examined the effects of ageing on the physiological function of the neuronal noradrenaline uptake system by comparing responses to cocaine in young adult (5 month) and aged (22 month) male Sprague-Dawley rats. In rat atria pre-incubated with [3H]-noradrenaline, cocaine (3-30 mumol/l) significantly augmented the 2 Hz stimulation-evoked release of noradrenaline in tissues from young but not from old rats. Cocaine (1 mg/kg) produced a greater increase of the pressor response to noradrenaline in young than in old pithed rats. Cocaine significantly increased the tachycardia to noradrenaline only in young pithed rats, but in old pithed rats the duration of the response to noradrenaline was significantly increased. It is concluded that ageing in the rat is associated with a decreased function of the neuronal noradrenaline uptake system, at least in the cardiovascular system.