title: Reduction of the argyrophilic nucleolar organizing region associated protein synthesis with age in buccal epithelial cells of healthy individuals.
abstract: BACKGROUND
  Nucleolus organizer regions (NORs) consist of the rRNA coding gene family (rDNA) in the cell nucleus. The argyrophilic proteins are selectively stained with silver nitrate and bind these regions. It was reported that NOR (rDNA) activity decreases in human lymphocytes, fibroblasts and bone marrow with age. However, to our knowledge there have not been any studies related to the NORs in oral epithelial cells of healthy individuals.
  
  
  OBJECTIVE
  Our aim is to detect any correlation between age and Total AgNOR area/Total nucleus area (TAA/TNA) values in buccal epithelial cells of healthy individuals.
  
  
  METHODS
  Oral epithelial cells from 50 healthy individuals (age range of 2-80 years old) were spread onto a clean glass slide, air dried and fixed. Then the AgNOR staining protocol was performed on these cells. TAA/TNA ratio and AgNOR dots were calculated using software. From each person 50 oral epithelial cells were evaluated.
  
  
  RESULTS
  Statistically significant correlations were found between mean TAA/TNA values and age (Rsq = 0.534, p < 0.001 for linear and Rsq = 0.728, p < 0.0001 for polynominal regression), and between AgNOR number and age (Rsq = 0.621, p < 0.001 for linear and Rsq = 0.693, p < 0.0001 for polynominal regression).
  
  
  CONCLUSIONS
  There is a significant correlation between age and AgNOR amount (ribosome biosynthesis rate) in buccal epithelial cells of healthy individuals. AgNORs in buccal epithelial cells may be used for detection of age.
authors.affiliation: Department of Medical Biology, Medical School, Erciyes University, Kayseri, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Selvi
authors.forename: Halil
authors.initials: H
authors.lastname: Demirtas
authors.forename: Recep
authors.initials: R
authors.lastname: Eroz
authors.forename: Nalan
authors.initials: N
authors.lastname: Imamoglu
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D034961:Antigens, Nuclear / Q000096:biosynthesis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism*
chemical_list: D034961:Antigens, Nuclear; C051963:nucleolar organizer region associated proteins