title: Peripherally circulating ghrelin does not mediate alcohol-induced reward and alcohol intake in rodents.
abstract: BACKGROUND
  Development of alcohol dependence, a chronic and relapsing disease, largely depends on the effects of alcohol on the brain reward systems. By elucidating the mechanisms involved in alcohol use disorder, novel treatment strategies may be developed. Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor 1A, acts as an important regulator of energy balance. Recently ghrelin and its receptor were shown to mediate alcohol reward and to control alcohol consumption in rodents. However, the role of central versus peripheral ghrelin for alcohol reward needs to be elucidated.
  
  
  METHODS
  Given that ghrelin mainly is produced by peripheral organs, the present study was designed to investigate the role of circulating endogenous ghelin for alcohol reward and for alcohol intake in rodents.
  
  
  RESULTS
  We showed that the Spiegelmer NOX-B11-2, which binds and neutralizes acylated ghrelin in the periphery with high affinity and thus prevents its brain access, does not attenuate the alcohol-induced locomotor activity, accumbal dopamine release and expression of conditioned place preference in mice. Moreover, NOX-B11-2 does not affect alcohol intake using the intermittent access 20% alcohol 2-bottle-choice drinking paradigm in rats, suggesting that circulating ghrelin does not regulate alcohol intake or the rewarding properties of alcohol. In the present study, we showed however, that NOX-B11-2 reduced food intake in rats supporting a role for circulating ghrelin as physiological regulators of food intake. Moreover, NOX-B11-2 did not affect the blood alcohol concentration in mice.
  
  
  CONCLUSIONS
  Collectively, the past and present studies suggest that central, rather than peripheral, ghrelin signaling may be a potential target for pharmacological treatment of alcohol dependence.
authors.affiliation: Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Jerlhag
authors.forename: Lisa
authors.initials: L
authors.lastname: Ivanoff
authors.forename: Axel
authors.initials: A
authors.lastname: Vater
authors.forename: Jörgen A
authors.initials: JA
authors.lastname: Engel
mesh_terms: D000428:Alcohol Drinking / Q000097:blood* / Q000503:physiopathology; D000818:Animals; D015415:Biomarkers / Q000097:blood; D054439:Ghrelin / Q000037:antagonists & inhibitors / Q000097:blood*; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009841:Oligonucleotides / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012201:Reward
chemical_list: D015415:Biomarkers; D054439:Ghrelin; C509286:NOX-B11-2; D009841:Oligonucleotides
keywords: Alcohol; Food Intake; Ghrelin; Reward; Spiegelmer