Effects of B-HT 920 and B-HT 933 on dopamine and noradrenaline autoreceptors in the rat brain.
B-HT 920 at low doses inhibited the accumulation of DOPA following treatment with reserpine and a DOPA decarboxylase inhibitor in the dopamine-, but not in the noradrenaline-predominant regions of the rat brain. B-HT 933 selectively inhibited this DOPA accumulation in the noradrenaline-predominant regions. These effects of B-HT 920 and B-HT 933 were completely antagonized by haloperidol and yohimbine, respectively. The rat motor activity was reduced by B-HT 920 and it was restored following apomorphine. B-HT 933 decreased the motor activity by a yohimbine-sensitive mechanism. The results indicate that B-HT 920 can selectively and potently stimulate the dopamine autoreceptors whereas B-HT 933 can selectively stimulate the noradrenaline autoreceptors.
D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects*; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011954:Receptors, Dopamine / Q000187:drug effects*
D001381:Azepines; D011941:Receptors, Adrenergic; D011954:Receptors, Dopamine; D004295:Dihydroxyphenylalanine; C024763:talipexole; C015603:azepexole; D006220:Haloperidol; D004298:Dopamine