title: Presence of obestatin in breast milk: relationship among obestatin, ghrelin, and leptin in lactating women.
abstract: OBJECTIVE
  The peptide hormones ghrelin and leptin have been found in blood and breast milk. This study was undertaken to investigate whether breast milk also contains obestatin, which is derived from the same gene as ghrelin but has opposite actions, and to characterize the relations among serum and milk ghrelin, obestatin, and leptin levels in lactating mothers.
  
  
  METHODS
  Venous blood, colostrum, and mature milk were obtained from healthy lactating women (n = 31) just before suckling. The ghrelin and obestatin concentrations were determined by radioimmunoassay. Leptin levels were measured by enzyme-amplified sensitivity immunoassay.
  
  
  RESULTS
  Obestatin levels in colostrum (538.9 pg/mL) and mature milk (528.5 pg/mL) were more than twice the corresponding blood levels (270.3 and 289.4 pg/mL, respectively). In contrast, leptin levels in colostrum (2.01 ng/mL) and mature milk (2.04 ng/mL) were more than five-fold lower than the corresponding blood levels (11.54 ng/mL). There was no correlation between breast milk ghrelin levels and leptin (r = -0.18, P > 0.05). However, there was a positive correlation between leptin levels in breast milk and blood (r = 0.369, P < 0.05).
  
  
  CONCLUSIONS
  The origin of milk obestatin is not currently known, but it comes from the blood or breast and may drain through the mammary glands into the milk. Ghrelin, obestatin, and leptin in the milk may directly affect appetite and their levels may be related to the regulation of energy balance and the pathogenesis of obesity.
authors.affiliation: Department of Biochemistry and Clinical Biochemistry, School of Medicine, Firat University, Firat Medical Center, Elazig, Turkey. saydin1@hotmail.com
authors.forename: Suleyman
authors.initials: S
authors.lastname: Aydin
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Ozkan
authors.forename: Fazilet
authors.initials: F
authors.lastname: Erman
authors.forename: Bilgin
authors.initials: B
authors.lastname: Gurates
authors.forename: Nermin
authors.initials: N
authors.lastname: Kilic
authors.forename: Ramis
authors.initials: R
authors.lastname: Colak
authors.forename: Tugba
authors.initials: T
authors.lastname: Gundogan
authors.forename: Zekiye
authors.initials: Z
authors.lastname: Catak
authors.forename: Mahmut
authors.initials: M
authors.lastname: Bozkurt
authors.forename: Okhan
authors.initials: O
authors.lastname: Akin
authors.forename: Yasar
authors.initials: Y
authors.lastname: Sen
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sahn
mesh_terms: D000328:Adult; D003126:Colostrum / Q000737:chemistry; D005260:Female; D054439:Ghrelin / Q000032:analysis* / Q000097:blood; D006801:Humans; D007774:Lactation / Q000097:blood / Q000378:metabolism*; D020738:Leptin / Q000032:analysis* / Q000097:blood; D008895:Milk, Human / Q000737:chemistry*; D036361:Peptide Hormones / Q000032:analysis* / Q000097:blood; D049590:Postpartum Period
chemical_list: D054439:Ghrelin; D020738:Leptin; D036361:Peptide Hormones; C505799:obestatin, human