title: Long-lasting increased pain sensitivity in rat following exposure to heroin for the first time.
abstract: Acute dependence, defined as a precipitation of somatic signs by an antagonist, may occur after a single administration of an opiate drug. Because hyperalgesia is a consistent sign of the withdrawal syndrome, we tested the effectiveness of heroin, an opiate used by addicts, to induce pain facilitation even after a first exposure to the drug. In opiate-naive rats, subcutaneous injection of heroin induced analgesia followed by allodynia, a decrease in pain threshold. This latter phenomenon was observed in the absence of noxious stimuli and lasted several days. An N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801 prevented such long-lasting allodynia. These results suggest that allodynia is an early sign reflecting neural plasticity associated with the development of dependence.
authors.affiliation: INSERM U259, Université Victor Segalen, Bordeaux II, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Laulin
authors.forename: A
authors.initials: A
authors.lastname: Larcher
authors.forename: E
authors.initials: E
authors.lastname: Célèrier
authors.forename: M
authors.initials: M
authors.lastname: Le Moal
authors.forename: G
authors.initials: G
authors.lastname: Simonnet
mesh_terms: D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D003932:Heroin / Q000494:pharmacology*; D008297:Male; D009294:Narcotics / Q000494:pharmacology*; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D014828:Vocalization, Animal / Q000187:drug effects
chemical_list: D018691:Excitatory Amino Acid Antagonists; D009294:Narcotics; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate; D003932:Heroin