title: Influences of locus coeruleus lesions and reserpine treatment on opioid physical dependence in rats.
abstract: OBJECTIVE
  To study the role of locus coeruleus (LC) noradrenergic neurons in the opioid dependence.
  
  
  METHODS
  Chemical lesion of LC was produced by 6-hydroxydopamine (4 micrograms in 1 microL). Reserpine (Res) was used to deplete central noradrenaline. Composite scores of naloxone (4 mg.kg-1, ip) precipitated abstinence syndromes were calculated and the magnitude of weight loss was determined in chronic morphine (Mor)- or dihydroetorphine (DHE)-treated rats.
  
  
  RESULTS
  Lesions of LC made Mor, but not DHE, abstinence syndrome more serious. Multiple doses of Res (0.5 mg.kg-1.d-1 x 3 d) increased scores of Mor and DHE abstinence syndrome, made worse the loss of body weight in chronic Mor-, but not DHE-, treated rats. A single dose of Res (0.5 mg.kg-1) speeded up the development of physical dependence on Mor.
  
  
  CONCLUSIONS
  The LC noradrenergic neurons play a role in suppression of some withdrawal symptoms.
authors.affiliation: Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China.
authors.forename: H
authors.initials: H
authors.lastname: Miao
authors.forename: B Y
authors.initials: BY
authors.lastname: Qin
mesh_terms: D000818:Animals; D001835:Body Weight; D005048:Etorphine / Q000031:analogs & derivatives*; D005260:Female; D008125:Locus Coeruleus / Q000503:physiopathology*; D008297:Male; D009021:Morphine Dependence / Q000503:physiopathology*; D009474:Neurons / Q000502:physiology; D009293:Opioid-Related Disorders / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D012110:Reserpine; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*
chemical_list: D005048:Etorphine; D012110:Reserpine; C034765:18,19-dihydroetorphine