Stimulation of presynaptic dopamine autoreceptors by 4-(2-di-n-propylaminoethyl) indole (DPAI).
The dopaminergic activity of 4-(2-di-n-propylaminoethyl)indole (DPAI) was investigated. In animal models for postsynaptic dopaminergic activity DPAI showed only very weak or no effects. In rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal tract, very weak contralateral turning behavior was induced in 4/6 rats. DPAI did not induce stereotyped behavior but caused a pronounced reduction in locomotor activity. In male rats pretreated with reserpine, DPAI lowered serum prolactin levels. Levels of homovanillic acid (HVA) were monitored in the striatum of the chloral hydrate anesthetized rat by means of in vivo voltammetry. DPAI administration reduced the faradaic peak corresponding to HVA. In rats pretreated with the decarboxylase inhibitor, NSD-1015, DPAI blocked the accumulation of dopa in response to gamma-butyrolactone. The results of this study indicate that DPAI possesses a high degree of selectivity for presynaptic dopamine autoreceptors, and little or no effect on postsynaptic dopamine receptors.
D000818:Animals; D003342:Corpus Striatum / Q000032:analysis; D003345:Corticosterone / Q000097:blood; D004295:Dihydroxyphenylalanine / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D006719:Homovanillic Acid / Q000032:analysis; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011388:Prolactin / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D013239:Stereotyped Behavior / Q000187:drug effects; D013378:Substantia Nigra / Q000502:physiology
D007211:Indoles; D011954:Receptors, Dopamine; D004295:Dihydroxyphenylalanine; C040577:4-(2-di-N-propylaminoethyl)indole; D011388:Prolactin; D003345:Corticosterone; D006719:Homovanillic Acid