title: Detection of nitric oxide by electron paramagnetic resonance spectroscopy during rejection and graft-versus-host disease after small-bowel transplantation in the rat.
abstract: BACKGROUND
  Our previous observation that nitric oxide (NO) is synthesized during antigen-specific immune reactions in vitro led us to investigate whether NO is produced during the in vivo immune response to a vascularized organ allograft.
  
  
  METHODS
  Orthotopic small-bowel transplantation in the rat was performed by standard microsurgical techniques in the LBNF1 to Lewis (rejection alone), Lewis to LBNF1 (graft-versus-host disease [GVHD] alone), and a syngeneic strain combination with and without immunosuppressive therapy with FK 506. The recipient serum NO2-/NO3- levels (stable end products of NO metabolism) were measured and erythrocytes were evaluated for the presence of nitrosylferrohemoglobin (specific for NO bound to hemoglobin).
  
  
  RESULTS
  Animals that acutely rejected small-bowel allografts or suffered from acute GVHD showed significantly elevated serum NO2-/NO3- levels on days 6 and 9, and nitrosylferrohemoglobin electron paramagnetic resonance signals of different intensity were detected on days 3, 6, and 9. FK 506-treated allograft recipients and recipients of syngeneic grafts showed normal serum NO2-/NO3- levels and lacked nitrosylferrohemoglobin signals at all time points.
  
  
  CONCLUSIONS
  This study indicates that NO is produced early during the course of small-bowel allograft rejection and GVHD and might therefore serve as a simple marker to detect such immune reactions.
authors.affiliation: Department of Surgery, Universitätsklinikum Rudolf Virchow, Free University of Berlin, Germany.
authors.forename: J M
authors.initials: JM
authors.lastname: Langrehr
authors.forename: A R
authors.initials: AR
authors.lastname: Müller
authors.forename: H A
authors.initials: HA
authors.lastname: Bergonia
authors.forename: T D
authors.initials: TD
authors.lastname: Jacob
authors.forename: T K
authors.initials: TK
authors.lastname: Lee
authors.forename: W H
authors.initials: WH
authors.lastname: Schraut
authors.forename: J R
authors.initials: JR
authors.lastname: Lancaster
authors.forename: R A
authors.initials: RA
authors.lastname: Hoffman
authors.forename: R L
authors.initials: RL
authors.lastname: Simmons
mesh_terms: D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D006084:Graft Rejection; D006086:Graft vs Host Disease / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D007421:Intestine, Small / Q000473:pathology / Q000637:transplantation*; D008297:Male; D009569:Nitric Oxide / Q000097:blood / Q000378:metabolism*; D009609:Nitrous Oxide / Q000097:blood; D011183:Postoperative Complications; D051381:Rats; D011917:Rats, Inbred Lew; D011919:Rats, Inbred Strains
chemical_list: D009569:Nitric Oxide; D009609:Nitrous Oxide