Dopaminergic effects of non-hydroxylated rigid analogs of apomorphine.

A series of rigid analogs of apomorphine lacking aromatic hydroxyl substitutents were evaluated for dopaminergic properties. Three compounds, N-methyl-N-propyl-2-aminotetralin (Me-Pr-2-AT), N-N-dipropyl-2-aminotetralin (Di-pr-2-AT) and N,N-dipropyl-2-aminoindane (Di-Pr-2-AI) induced emesis in dogs, contralateral circling in unilaterally lesioned rats, and inhibited prolactin secretion. The induced circling responses, however, were attenuated by prior treatment with alpha-methyl-p-tyrosine methyl ester (AMPTME) and the compounds were weak inhibitors of 3-H-dopamine binding in calf caudate homogenates. The possibility that these agents may be metabolically activated in vivo is discussed.