title: Effects of 18-methoxycoronaridine on ghrelin-induced increases in sucrose intake and accumbal dopamine overflow in female rats.
abstract: BACKGROUND
  18-methoxycoronaridine (18-MC), a selective antagonist of α3β4 nicotinic receptors, has been previously shown, in rats, to reduce the self-administration of several drugs of abuse, reduce operant responding for sucrose, and prevent the development of sucrose-induced obesity. It has become increasingly apparent that there is a significant overlap between the systems regulating drug reward and food intake, therefore, we investigated whether 18-MC might modulate the effects of ghrelin, one of several orexigenic peptides recently implicated in both feeding and drug reward.
  
  
  OBJECTIVE
  In female Sprague-Dawley rats, we determined whether acute 18-MC treatment would reduce both ghrelin-induced increases in sucrose intake and ghrelin-elicited increases in accumbal dopamine levels.
  
  
  RESULTS
  Pretreatment with 18-MC (20 mg/kg, i.p.), given prior to the administration of ghrelin (1 μg, lateral ventricle), blocked ghrelin-induced increases in sucrose (5%) intake in a two-bottle open access paradigm. Using in vivo microdialysis, 18-MC (both 20 and 40 mg/kg) prevented ghrelin (2 μg, intraventral tegmental area)-induced increases in extracellular dopamine in the nucleus accumbens. 18-MC had no effect on deposition of fat or on serum levels of glucose, triglycerides, and cholesterol in ghrelin-treated rats.
  
  
  CONCLUSIONS
  The present results suggest that one potential mechanism by which 18-MC exerts its effects on palatable food consumption is via modulation of ghrelin's effects.
authors.affiliation: Center for Neuropharmacology and Neuroscience MC-136, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA. mccalls@mail.amc.edu
authors.forename: Sarah E
authors.initials: SE
authors.lastname: McCallum
authors.forename: Olga D
authors.initials: OD
authors.lastname: Taraschenko
authors.forename: Ethan R
authors.initials: ER
authors.lastname: Hathaway
authors.forename: Melanie Y
authors.initials: MY
authors.lastname: Vincent
authors.forename: Stanley D
authors.initials: SD
authors.lastname: Glick
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D002784:Cholesterol / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism*; D004327:Drinking Behavior / Q000187:drug effects*; D004347:Drug Interactions; D005260:Female; D054439:Ghrelin / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism; D007050:Ibogaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D007276:Injections, Intraventricular; D017551:Microdialysis; D009714:Nucleus Accumbens / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000008:administration & dosage*; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D014280:Triglycerides; D015102:3,4-Dihydroxyphenylacetic Acid; D007050:Ibogaine; D013395:Sucrose; D002784:Cholesterol; C103345:18-methoxycoronaridine; D004298:Dopamine; D006719:Homovanillic Acid