title: Role of hypothalamic monoamines in nicotine-induced anorexia in menopausal rats.
abstract: BACKGROUND
  Nicotine reduces body weight by reducing appetite. Estradiol modulates food intake. Menopause or ovariectomy (Ovx) increases food intake and body weight. Nicotine and estradiol individually influence hypothalamic dopamine (DA) and serotonin (5-HT), whose interaction influences food intake and body weight. We investigated whether lower weight gain in menopausal smokers is mediated via changes in hypothalamic DA/5-HT.
  
  
  METHODS
  Ovx or sham-operated female rats had 2 microdialysis guide cannulas simultaneously implanted in ipsilateral ventromedial nucleus of hypothalamus (VMN) and contralateral lateral hypothalamic area (LHA). Rats were divided into 4 groups and received a continuous subcutaneous infusion of nicotine or saline Ovx and sham. DA and 5-HT in LHA and VMN were measured by in vivo microdialysis.
  
  
  RESULTS
  Nicotine infusion decreased food intake and body weight in Ovx and sham groups. Increase in LHA-DA and VMN-5-HT in sham group occurred with nicotine, whereas an increase in VMN-DA in Ovx groups with and without nicotine and VMN-5-HT in Ovx group with nicotine was observed.
  
  
  CONCLUSIONS
  In the presence of estradiol (ovary intact sham-operated rats), nicotine lowers food intake and body weight via increased LHA-DA and VMN-5-HT. In menopause (Ovx rats), nicotine lowers food intake and body weight only via increased VMN-DA and 5-HT. Data show that lower weight gain is mediated via changes in hypothalamic monoamines, primarily via ventromedial hypothalamus.
authors.affiliation: Surgical Metabolism and Nutrition Laboratory, Department of Surgery, University Hospital, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: M M
authors.initials: MM
authors.lastname: Meguid
authors.forename: G
authors.initials: G
authors.lastname: Miyata
authors.forename: M
authors.initials: M
authors.lastname: Varma
authors.forename: S O
authors.initials: SO
authors.lastname: Fetissov
mesh_terms: D000818:Animals; D000855:Anorexia / Q000139:chemically induced / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004435:Eating / Q000187:drug effects / Q000502:physiology; D005260:Female; D007026:Hypothalamic Area, Lateral / Q000187:drug effects / Q000378:metabolism; D008593:Menopause / Q000502:physiology*; D017551:Microdialysis; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: D018722:Nicotinic Agonists; D012701:Serotonin; D009538:Nicotine; D004298:Dopamine