title: A novel assay system for myeloperoxidase activity in whole saliva.
abstract: OBJECTIVE
  The application of a novel assay system for the direct measurement of MPO (myeloperoxidase) activity in whole saliva.
  
  
  METHODS
  The assay system employs a novel sensitive substrate from 3,3'-diaminobenzidine (DAB) and guaiacol in the presence of dapsone (4,4'-diaminodiphenylsulfone) to determine MPO activity in whole saliva using an original "sandwich" test-disk (DEAE-cellulose paper and cellulose chromatography paper). The saliva (0.1 mL) was directly applied to the sandwich test-disk, and then 0.1 mL of the substrate solution containing 1 mM dapsone in 0.3 M Tris-HCl buffer (pH 7.5) was added. After incubation for 30 min at room temperature, absorbance on the test-disk was measured at 460 nm with an optical analyzer.
  
  
  RESULTS
  The assay system was shown to distinguish MPO from salivary peroxidase in whole mixed saliva and was sensitive, easy and cheap. The assays revealed that MPO activity in whole saliva from subjects with periodontal disease was significantly higher than in saliva from healthy subjects. There was also a significant positive correlation between MPO activity and the probing depth of subgingival pockets (r=0.736, p<0.001).
  
  
  CONCLUSIONS
  These results indicate that this novel assay system for measurement of MPO is a useful technique for predicting the progression of periodontal disease.
authors.affiliation: Institute of Well Being, Fuji Women's University, 061-3204 Ishikari, Hokkaido, Japan. wsakamot@fujijoshi.ac.jp
authors.forename: Wataru
authors.initials: W
authors.lastname: Sakamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fujii
authors.forename: Takashi
authors.initials: T
authors.lastname: Kanehira
authors.forename: Kozo
authors.initials: K
authors.lastname: Asano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Izumi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002848:Chromatography, DEAE-Cellulose / Q000379:methods; D004789:Enzyme Activation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010510:Periodontal Diseases / Q000175:diagnosis / Q000201:enzymology*; D009195:Peroxidase / Q000032:analysis / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry / Q000201:enzymology*; D012471:Salivary Proteins and Peptides / Q000032:analysis / Q000378:metabolism*
chemical_list: D012471:Salivary Proteins and Peptides; D009195:Peroxidase