The effect of some new antidepressants on apomorphine-induced hypothermia in mice

Abstract

Imipramine-like tricyclic antidepressants antagonize hypothermia induced by apomorphine in mice (Lapin & Samsonova 1968; Schelkunov 1968, 1977; Fuxe & Sjöqvist 1972; Maj et al 1974; Puech et al 1978); this phenomenon has been used by some authors as a test for the antidepressant activity. Therefore, we have examined the effect of some new antidepressants in this test, especially as some of them differ in their mechanism of action from imipramine-like drugs. The drugs used were: nomifensine, an inhibitor of the dopamine and noradrenaline (NA) uptake (Hunt et al 1974; Schacht & Heptner 1974), two specific inhibitors of 5-hydroxytryptamine (5-HT) uptake, femoxetine (FG 4963) (Buus Lassen et al 1975) and poroxetine (FG 7051) (Petersen et al 1977), two other antidepressants whose main characteristic was the blockade of central 5-HT receptors, i.e. mianserin (van Riezen 1972) and trazodone (Baran et al 1979). We also included pizotifen, a drug used in migraine prophylaxis (see Speight & Avery 1972) but exerting an antidepressant effect (Standal 1977; Banki 1978) and a potent central anti 5-HT activity (Dixon et al 1977; Przegalinski et al 1979). For comparison, the effect of four tricyclic antidepressants (imipramine, desipramine, amitriptyline and chlorimipramine) was also studied.