title: Plasma levels of leptin, omentin, collagenous repeat-containing sequence of 26-kDa protein (CORS-26) and adiponectin before and after oral glucose uptake in slim adults.
abstract: BACKGROUND
  Adipose tissue secreted proteins are collectively named adipocytokines and include leptin, adiponectin, resistin, collagenous repeat-containing sequence of 26-kDa protein (CORS-26) and omentin. Several of these adipocytokines influence insulin sensitivity and glucose metabolism and therefore systemic levels may be affected by oral glucose uptake. Whereas contradictory results have been published for leptin and adiponectin, resistin has not been extensively investigated and no reports on omentin and CORS-26 do exist.
  
  
  METHODS
  Therefore the plasma levels of these proteins before and 120 min after an oral glucose load were analyzed in 20 highly-insulin sensitive, young adults by ELISA or immunoblot.
  
  
  RESULTS
  Circulating leptin was reduced 2 h after glucose uptake whereas adiponectin and resistin levels are not changed. Distribution of adiponectin and CORS-26 isoforms were similar before and after glucose ingestion. Omentin is highly abundant in plasma and immunoblot analysis revealed no alterations when plasma levels before and 2 h after glucose intake were compared.
  
  
  CONCLUSIONS
  Taken together our data indicate that only leptin is reduced by glucose uptake in insulin-sensitive probands whereas adiponectin and resistin are not altered. CORS-26 was demonstrated for the first time to circulate as high molecular weight form in plasma and like omentin was not influenced by oral glucose load. Omentin was shown to enhance insulin-stimulated glucose uptake but systemic levels are not correlated to postprandial blood glucose.
authors.affiliation: Department of Internal Medicine I, Regensburg University Hospital, D-93042 Regensburg, Germany. sylvia_wurm@hotmail.com
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wurm
authors.forename: Markus
authors.initials: M
authors.lastname: Neumeier
authors.forename: Johanna
authors.initials: J
authors.lastname: Weigert
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäffler
authors.forename: Christa
authors.initials: C
authors.lastname: Buechler
mesh_terms: D052242:Adiponectin / Q000097:blood*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D016207:Cytokines / Q000097:blood* / Q000235:genetics; D005260:Female; D058851:GPI-Linked Proteins; D005951:Glucose Tolerance Test; D006801:Humans; D015151:Immunoblotting; D037102:Lectins / Q000097:blood* / Q000235:genetics; D020738:Leptin / Q000097:blood*; D008297:Male; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D013851:Thinness; D048069:Tumor Necrosis Factors
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; C506069:C1QTNF3 protein, human; D016207:Cytokines; D058851:GPI-Linked Proteins; C432397:ITLN1 protein, human; D037102:Lectins; D020738:Leptin; D011506:Proteins; D048069:Tumor Necrosis Factors