Evidence for the role of noradrenaline in some effects of quipazine.

In mice, quipazine has shown several behavioral effects: It antagonizes hypothermia induced by a high dose of apomorphine without altering climbing or stereotyped behavior; it antagonizes oxotremorine-induced hypothermia without altering tremors or peripheral signs; and it increases the toxicity of yohimbine. These three responses are considered to be predictive of an antidepressive action; in these three tests the effects of quipazine are inhibited by D,L-propranolol but not by D-propranolol or methysergide. Quipazine, in mice pretreated with pargyline, induced head twitches which were inhibited by methysergide but not by D,L-propranolol. Quipazine, in addition to its well-known serotonergic effects, seems to have beta-adrenergic properties which should be kept in mind when this drug is used as a pharmacological tool and which suggest that the beta-adrenergic system is implied in depression.