title: Antinociceptive and stimulant effects of morphine after chemical sympathectomy.
abstract: The modifications produced by 6-hydroxydopamine (6-OHDA) on the analgesic and toxic effects of morphine have been studied in mice and cats. After intracerebral injections of 6-OHDA, mice had a lower threshold for morphine-induced convulsions. Morphine analgesia assayed by the phenylquinone test was apparently antagonized in the 6-OHDA pretreated mice, but the 6-OHDA mice showed more reactivity to the phenylquinone. Intraventricular injection of 6-OHDA in cats produced an acute syndrome with mydriasis, bradycardia, bradypnea, hypothermia and EEG slowing, which subsided after several days, 6-OHDA was successful in blocking the morphine mania, but the animals died within 24 h.
mesh_terms: D000588:Amines / Q000378:metabolism; D000698:Analgesia; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002415:Cats; D004569:Electroencephalography; D006892:Hydroxydopamines / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D011809:Quinones / Q000494:pharmacology; D012640:Seizures / Q000139:chemically induced; D013564:Sympathetic Nervous System / Q000187:drug effects*
chemical_list: D000588:Amines; D006892:Hydroxydopamines; D011809:Quinones; D009020:Morphine