Highlights ► The involvement of transmitters in the anxiolytic action of GH-RH antagonist, MZ-4-71, has been tested in plus maze. ► In the experiments the animals were pretreated with phenoxybenzamine, prazosin, yohimbine, methysergide,cyproheptadine and bicuculline. ► The anxiolytic action of MZ-471 was elicited via α1/α2-adrenergic, 5HT1/5HT2 serotonergic and GABA-A-ergic mechanism.