Detection of nitric oxide by electron paramagnetic resonance spectroscopy during rejection and graft-versus-host disease after small-bowel transplantation in the rat.
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.
Langrehr
J M
JM
Department of Surgery, Universitätsklinikum Rudolf Virchow, Free University of Berlin, Germany.
Müller
A R
AR
Bergonia
H A
HA
Jacob
T D
TD
Lee
T K
TK
Schraut
W H
WH
Lancaster
J R
JR
Hoffman
R A
RA
Simmons
R L
RL
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
D009569:Nitric Oxide; D009609:Nitrous Oxide