Effects of antidepressant drugs on noradrenaline accumulation and contractile responses in the rat anococcygeus muscle.

1 The effect of a series of antidepressant drugs on noradrenaline accumulation was studied in the isolated anococcygeus muscle of the rat. 2 The most potent inhibitors of noradrenaline accumulation were nortriptyline, desipramine and protriptyline. Opipramol, trimipramine and iprindole were active only in high concentrations. 3 Contractions of the anococcygeus muscle produced by noradrenaline were strongly potentiated by nortriptyline, desipramine and protriptyline. Other uptake inhibitors were less active in potentiating the noradrenaline response. 4 Nortriptyline, in concentrations that potentiated the action of noradrenaline, reduced or abolished the response to tyramine.