title: Effects of cigarette smoke exposure and its cessation on body weight, food intake and circulating leptin, and ghrelin levels in the rat.
abstract: BACKGROUND
  Smoking is associated with loss of body weight (BW) and reduced appetite, while smoking abstinence with the opposite effect. The role of peripheral signaling by appetite-controlling hormones leptin and ghrelin is not clear. In the present study, the relationship of circulating leptin and ghrelin with BW and food intake rate (FIR) changes was studied during cigarette smoke exposure (CSE) and after its cessation in the rat.
  
  
  METHODS
  Male Wistar rats were subjected to CSE for 8 weeks by confinement to plexiglass chambers (Group S). Control animals were confined to identical chambers without smoke (Group C). During CSE and an equivalent follow-up period, BW and FIR was recorded and serum leptin and ghrelin levels were measured.
  
  
  RESULTS
  A sharp decrease in BW was noted during the first 4 weeks of CSE, while FIR, after a substantial decrease noted at Week 1, returned to control levels. Thereafter, rats started to regain their BW until they reached control levels by the 1st week postCSE. BW regain was accompanied by a rebound increase of FIR, which plateaued during the first 4 weeks postCSE and then normalized. Serum leptin was decreased in Group S during both periods, normalizing at the 7th week postCSE. Ghrelin levels did not differ between groups.
  
  
  CONCLUSIONS
  Circulating leptin could not explain by its own BW and FIR changes during the first few week of CSE in rats, in contrast to the rest of the CSE period as well as after its cessation. Serum ghrelin levels did not justify BW and FIR changes.
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, School of Medicine, Democritus University of Thrace, Alexandroupolis, Greece. pipsil@med.duth.gr
authors.forename: Petros
authors.initials: P
authors.lastname: Ypsilantis
authors.forename: Maria
authors.initials: M
authors.lastname: Politou
authors.forename: Constantinos
authors.initials: C
authors.lastname: Anagnostopoulos
authors.forename: Christina
authors.initials: C
authors.lastname: Tsigalou
authors.forename: Georgia
authors.initials: G
authors.lastname: Kambouromiti
authors.forename: Alexandros
authors.initials: A
authors.lastname: Kortsaris
authors.forename: Constantinos
authors.initials: C
authors.lastname: Simopoulos
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects*; D003367:Cotinine / Q000097:blood; D004435:Eating / Q000187:drug effects*; D054439:Ghrelin / Q000097:blood*; D020738:Leptin / Q000097:blood*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012907:Smoking / Q000009:adverse effects*
chemical_list: D054439:Ghrelin; D020738:Leptin; D003367:Cotinine