title: Plasma levels of active form of ghrelin during oral glucose tolerance test in patients with anorexia nervosa.
abstract: OBJECTIVE
  Ghrelin is an acylated peptide, whose octanoyl modification is essential for its biological activities. Previous studies demonstrated that fasting plasma ghrelin levels were high in anorectic patients, suggesting ghrelin may play an important role in the pathophysiology of anorexia nervosa. However, antibodies used in previous work to measure ghrelin concentrations in human blood do not distinguish between the active form of ghrelin (active ghrelin) and desacyl ghrelin with no biological activities. Therefore, we studied plasma levels of active ghrelin during oral glucose tolerance test (OGTT) in anorectic patients, using a radioimmunoassay (RIA) specific for active ghrelin.
  
  
  METHODS
  Active ghrelin response to OGTT was evaluated in five female anorectic patients and seven age-matched control females. All subjects were given a 75 g/225 ml glucose solution orally after overnight fasting. For RIA of active ghrelin, 1 N hydrogen chloride was added to the samples at final concentration of 0.1 N immediately after separation of plasma.
  
  
  RESULTS
  Plasma basal levels of active ghrelin were significantly higher in anorectic patients than in controls (52.1+/-10.5 vs 21.2+/-3.1 fmol/ml, P<0.01). They were significantly decreased during OGTT in anorectic patients and in controls, reaching a nadir of 49.0+/-7.7% and 57.3+/-4.5% of the basal levels, respectively.
  
  
  CONCLUSIONS
  These results suggest that hyperghrelinemia in anorectic patients is caused at least partly by increased secretion of active ghrelin and that glucose ingestion suppresses active ghrelin release in these patients.
authors.affiliation: College of Medical Technology, Kyoto University, Kyoto University Hospital, 53 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan. YN@itan.kyoto-u.ac.jp
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Nakai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hosoda
authors.forename: Kazuko
authors.initials: K
authors.lastname: Nin
authors.forename: Chizuru
authors.initials: C
authors.lastname: Ooya
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hayashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Akamizu
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
mesh_terms: D000856:Anorexia Nervosa / Q000097:blood* / Q000175:diagnosis; D005260:Female; D054439:Ghrelin; D005947:Glucose / Q000008:administration & dosage; D005951:Glucose Tolerance Test; D006801:Humans; D036361:Peptide Hormones / Q000097:blood* / Q000378:metabolism; D011863:Radioimmunoassay
chemical_list: D054439:Ghrelin; D036361:Peptide Hormones; D005947:Glucose