title: Influence of naloxone upon apomorphine-induced rotational behavior in rats with electrolytic versus chemolytical lesions of the substantia nigra.
abstract: In rats with unilateral electrolytic lesions of the substantia nigra, apomorphine induced ipsilateral rotational behavior that was significantly potentiated by naloxone. Yet, in rats with unilateral chemolytic (6-hydroxydopamine) lesions of the substantia nigra, apomorphine induced dose-dependent contralateral turning that was not influenced by pretreatment with even high doses of naloxone. High performance liquid chromatographic analysis of corpora striata from these rats revealed electrolytically-lesioned animals to have a 60-70% reduction in dopamine content while chemolytically-lesioned animals were virtually completely depleted of dopamine. These results suggest that striatal dopamine may be required for naloxone potentiation of apomorphine-induced effects in the rat rotational behavior paradigm.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D004357:Drug Synergism; D004572:Electrolysis; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012399:Rotation; D013239:Stereotyped Behavior / Q000187:drug effects*; D013378:Substantia Nigra / Q000502:physiology*
chemical_list: D009270:Naloxone; D001058:Apomorphine; D004298:Dopamine