title: Isotope tracing enhancement of chemiluminescence assays for nitric oxide research.
abstract: Chemiluminescence assays are used widely for the detection of nitric oxide (NO)-derived species in biological fluids and tissues. Here, we demonstrate that these assays can be interfaced with mass-sensitive detectors for parallel determination of isotopic abundance. Results obtained with tri-iodide and ascorbic acid-based reductive assays indicate that mass spectrometric detection enables NO isotope-tracing experiments to be carried out to a limit of detectability of a few picomoles, a sensitivity similar to that of standard gas phase chemiluminescence methods. The advantage afforded by mass spectrometric detection is demonstrated using the murine macrophage cell line J774, which is shown here to reduce 15NO3- to 15NO2- under anoxic conditions. The particular combination of an analytical and cellular system described here may hold promise for future characterization of the enzymatic pathways contributing to mammalian nitrate reductase activity, without background interference from 14NO2- derived from other sources.
authors.affiliation: Department of Physics, Centenary College of Louisiana, Shreveport, LA 71134, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Cornelius
authors.forename: Tuan
authors.initials: T
authors.lastname: Tran
authors.forename: Nicole
authors.initials: N
authors.lastname: Turner
authors.forename: Abigail
authors.initials: A
authors.lastname: Piazza
authors.forename: Lauren
authors.initials: L
authors.lastname: Mills
authors.forename: Ryan
authors.initials: R
authors.lastname: Slack
authors.forename: Sean
authors.initials: S
authors.lastname: Hauser
authors.forename: J Steven
authors.initials: JS
authors.lastname: Alexander
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Grisham
authors.forename: Martin
authors.initials: M
authors.lastname: Feelisch
authors.forename: Juan
authors.initials: J
authors.lastname: Rodriguez
mesh_terms: D000818:Animals; D002460:Cell Line; D007554:Isotopes; D008163:Luminescent Measurements / Q000379:methods*; D008264:Macrophages / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D009569:Nitric Oxide / Q000032:analysis / Q000737:chemistry*
chemical_list: D007554:Isotopes; D009569:Nitric Oxide