title: Expression of ghrelin in human salivary glands and its levels in saliva and serum in Chinese obese children and adolescents.
abstract: OBJECTIVE
  The aim of the present study was to reveal the expression characteristics of ghrelin in human three major salivary glands and to investigate saliva and serum ghrelin level and the relation with weight and lipid indices in Chinese children.
  
  
  METHODS
  Expression and distribution of ghrelin in parotid, submandibular, and sublingual glands were measured by reverse transcription-polymerase chain reaction and immunohistochemistry. Saliva and serum samples were collected from 194 Chinese children and adolescents (mean age 12.98 years). Ghrelin levels were tested by enzyme-linked immunosorbent assay. Significant differences were estimated by one-way ANOVA.
  
  
  RESULTS
  Ghrelin mRNA was expressed in parotid and submandibular glands, but was not detectable in sublingual glands. Ghrelin proteins were widespread in the cytoplasm of striated, intercalated and excretory ducts, as well as in serous acini of parotid and submandibular glands, but not in mucous acinar cells of sublingual glands. Saliva and serum ghrelin levels were increased along with BMI. There was positive correlation between saliva and serum ghrelin levels (r=0.534, P<0.01). Serum and saliva ghrelin levels were both significantly correlated with BMI (r=0.523, r=0.374, P<0.01, respectively), but not with blood lipid levels.
  
  
  CONCLUSIONS
  Parotid and submandibular glands were primary sources of ghrelin produced and released in saliva. Although whether salivary ghrelin could be useful in the diagnosis of obesity remains to be determined, salivary ghrelin might be a possible alternative to serum ghrelin for predicting obesity.
authors.affiliation: Department of Oral Pathology, Peking University School and Hospital of Stomatology, Beijing, PR China.
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Li
authors.forename: Zhi-Bin
authors.initials: ZB
authors.lastname: Chen
authors.forename: Bo-Chun
authors.initials: BC
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Lin
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Li
authors.forename: Sheng-Lin
authors.initials: SL
authors.lastname: Li
authors.forename: Chong
authors.initials: C
authors.lastname: Ding
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Wu
authors.forename: Guang-Yan
authors.initials: GY
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D044466:Asian People; D015992:Body Mass Index; D016022:Case-Control Studies; D002648:Child; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D054439:Ghrelin / Q000097:blood / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology*; D008297:Male; D009765:Obesity / Q000097:blood / Q000208:ethnology / Q000378:metabolism*; D050177:Overweight / Q000097:blood / Q000208:ethnology / Q000378:metabolism; D012016:Reference Values; D012463:Saliva / Q000378:metabolism*; D012469:Salivary Glands / Q000378:metabolism*; D013851:Thinness / Q000097:blood / Q000208:ethnology / Q000378:metabolism*; D014018:Tissue Distribution; D014280:Triglycerides / Q000097:blood
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D054439:Ghrelin; D014280:Triglycerides; D002784:Cholesterol