Article date: 1985/1/1
PubMed ID: 2987905
Journal name: Psychopharmacology. Supplementum (ISSN: 0179-8456)
Abnormal involuntary movements (AIMs, stereotyped or dyskinetic movements) were induced with different dopamine mimetics in rat, cat, and monkey. In the rat only stereotyped movements were observed, whereas in the cat dopamine agonists (apomorphine) preferentially induced dyskinesia but dopamine/noradrenaline uptake inhibitors (d-amphetamine, nomifensine) induced predominantly stereotypes; L-dopa induced an equal, low, number of both kinds of movements in the cat. In the monkey with bilateral lesions of the nigrostriatal dopamine pathways the AIMs could be divided into type 1 dyskinesia (behavioral), type 2 dyskinesia (oral and psychomotor), and chorea. GABA agonists (progabide, muscimol) had a biphasic action on apomorphine stereotypes in the rat, slightly (10%-20%) augmenting these movements at low doses and antagonizing (greater than 50%) them at higher doses. As these latter doses of progabide also antagonize apomorphine-induced circling in rats with a unilateral lesion of the substantia nigra, it is likely that this action is exerted at or beyond the dopamine target cell. In cats the dyskinetic movements induced by apomorphine were abolished by progabide. In contrast, L-dopa-induced stereotypies were resistant to the antidyskinetic action of progabide, and at low doses of L-dopa an increased incidence of stereotypies was noted. In the monkey, the type 1 dyskinesia following L-dopa and piribedil were also relatively resistant to progabide administration, whereas the type 2 dyskinesia and chorea were abolished by progabide. These studies are parallel to and support the clinical observations that dyskinetic movements following a direct action at the dopamine receptor (tardive dyskinesia) may be reversed by progabide whereas those associated with dopamine neuron activity, perhaps together with noradrenergic activation (L-dopa dyskinesia), are resistant to the antidyskinetic action of progabide.
Author List: Lloyd K G, Willigens M T, Goldstein M
Publication Types: Journal Article
Substances mentioned in the article: Receptors, Dopamine; Receptors, GABA-A; Nomifensine; Muscimol; progabide; Levodopa; gamma-Aminobutyric Acid; progabide acid; Piribedil; Apomorphine; Dextroamphetamine; Dopamine;
Mesh terms: Animals; Apomorphine/pharmacology; Brain/drug effects; Cats; Dextroamphetamine/pharmacology; Dopamine/metabolism; Dose-Response Relationship, Drug; Haplorhini; Humans; Levodopa/pharmacology; Motor Activity/drug effects; Muscimol/pharmacology; Nomifensine/pharmacology; Piribedil/pharmacology; Rats; Receptors, Dopamine/drug effects; Receptors, GABA-A/drug effects; Stereotyped Behavior/drug effects; gamma-Aminobutyric Acid/analogs & derivatives;