title: Selective and absolute quantification of endogenous hypochlorous acid with quantum-dot conjugated microbeads.
abstract: Endogenous hypochlorous acid (HOCl) secreted by leukocytes plays a critical role in both the immune defense of mammalians and the pathogenesis of various diseases intimately related to inflammation. We report the first selective and absolute quantification of endogenous HOCl produced by leukocytes in vitro and in vivo with a novel quantum dot-based sensor. An activated human neutrophil secreted 6.5 ± 0.9 × 10(8) HOCl molecules into its phagosome, and kinetic measurement for the secretions showed that the extracellular generation of HOCl was temporally retarded, but the quantity eventually attained a level comparable with its intraphagosomal counterpart with a delay of about 1.5 h. The quantity of HOCl secreted from the hepatic leukocytes of rats with or without stimulation of lipopolysaccharide was also determined. These results indicate a possibility to extend our approach to not only clinical settings for quantitative assessment of the bactericidal capability of isolated leukocytes of patients but also fundamental biomedical research that requires critical evaluation of the inflammatory response of animals.
authors.affiliation: Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, Taiwan.
authors.forename: Yi-Cyun
authors.initials: YC
authors.lastname: Yang
authors.forename: Hsueh-Han
authors.initials: HH
authors.lastname: Lu
authors.forename: Wei-Ti
authors.initials: WT
authors.lastname: Wang
authors.forename: Ian
authors.initials: I
authors.lastname: Liau
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000737:chemistry; D006801:Humans; D006997:Hypochlorous Acid / Q000032:analysis*; D007962:Leukocytes / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008863:Microspheres; D045663:Quantum Dots; D051381:Rats; D064586:Selenic Acid; D018036:Selenium Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D008070:Lipopolysaccharides; D018036:Selenium Compounds; D006997:Hypochlorous Acid; D064586:Selenic Acid