Dose related sequence of effects induced by the DA agonist 2-(N,N-dipropyl)-amino-5,6-dihydroxytetralin.

Abstract

2-N,N-dipropylamino 5,6-dihydroxytetralin (nPr2 ADTN), a potent dopaminergic agonist, induces the same polyphasic effects observed with apomorphine by Protais et al., (1983). The dose related sequence of behaviours in mice can be summed up as followed: to 0.9 to 3.9 micrograms.kg-1, a decrease in motor activity without any other effects; to 7.8 to 15.6 micrograms.kg-1, a return to control level or an increase in motility alone according to experimental conditions; to 31 to 62.5 micrograms.kg-1, a second phase of hypomotility when hypothermia develops; above 125 micrograms.kg-1, a second phase of hypermotility when both stereotypies and climbing behaviour appear. Hypothermia moreover, disappears. The effects of the nPr2 ADTN were compared with those of apomorphine obtained in others studies (Puech et al., 1974; Protais et al., 1983). The tetralin derivative differs from apomorphine in that the first phase of hypermotility it induces is greater, and that hypothermia disappears at high doses.