title: VMN dopaminergic graft and feeding pattern in obese Zucker rats.
abstract: OBJECTIVE
  To study the role of dopamine in the ventromedial hypothalamus (VMN) in the regulation of meal size and meal number during obesity.
  
  
  METHODS
  Embryonic mesencephalic cells rich in dopaminergic neurons from lean rats were grafted into the VMN of obese Zucker rats. Since food intake is the product of meal size and number, these variables were measured using a rat 'eater meter'. Dopamine and serotonin concentrations in the VMN were assayed in grafted and control rats via in vivo microdialysis and HPLC two months after transplantation.
  
  
  RESULTS
  Food intake increased in grafted rats due to an increase of both meal size and meal number 2 weeks after implantation and to an increase of meal size with insufficient compensatory decrease of meal number 2 months after transplantation. Grafted rats showed higher absolute dopamine and lower serotonin concentrations in the VMN.
  
  
  CONCLUSIONS
  It would appear that an increase of dopamine and a decrease of serotonin in the VMN of grafted obese rats may correlate with increase in meal number and meal size, respectively. Since obese Zucker rats usually display an enlarged meal size, we deduce from the data that chronically elevated VMN dopamine and low serotonin are involved in producing the large meal size observed during obesity.
authors.affiliation: Department of Surgery, University Hospital, SUNY HSC, Syracuse, NY 13210, USA.
authors.forename: S
authors.initials: S
authors.lastname: Fetissov
authors.forename: M M
authors.initials: MM
authors.lastname: Meguid
authors.forename: G
authors.initials: G
authors.lastname: Miyata
authors.forename: G F
authors.initials: GF
authors.lastname: Torelli
authors.forename: M
authors.initials: M
authors.lastname: Shafiroff
mesh_terms: D000818:Animals; D001835:Body Weight; D004298:Dopamine / Q000032:analysis / Q000502:physiology*; D004435:Eating / Q000502:physiology*; D004622:Embryo, Mammalian; D005502:Food; D007033:Hypothalamus, Middle / Q000737:chemistry / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000166:cytology*; D017551:Microdialysis; D009474:Neurons / Q000637:transplantation*; D009765:Obesity / Q000503:physiopathology*; D051381:Rats; D011924:Rats, Zucker; D012701:Serotonin / Q000032:analysis / Q000378:metabolism
chemical_list: D012701:Serotonin; D004298:Dopamine