Simultaneous evaluation of nitric oxide synthesis and tissue oxygenation in rat liver allograft rejection using near-infrared spectroscopy.
Near-infrared (NIR) spectroscopy was applied to rat liver allografts for assessing nitric oxide (NO) synthesis and tissue oxygenation as a means of monitoring the rejection response following liver transplantation. Orthotopic liver transplantation was performed in rats, which were assigned to three groups as follows: group 1, a syngeneic combination (lewis to Lewis); group 2, an allogeneic combination (ACI to Lewis); and group 3, an allogeneic combination treated with 15-deoxyspergualin. NIR spectroscopy was performed on the grafts in recipients, and the relative changes in nitrosyl-Hb (NO bound to erythrocyte hemoglobin), oxy-Hb, and oxidized cytochrome oxidase (Cyt.aa3) were obtained. The level of nitrosyl-Hb was significantly elevated from postoperative day (POD) 3 in group 2 compared with that in group 1, which remained constant (P < 0.05). In group 3, the elevation was significantly suppressed. These data indicate that the alloimmune response is associated with a dramatic change in NO synthesis in grafted livers. In a separate experiment, NO synthesis was also increased after long cold preservation (24 hr) in syngeneic liver transplants. However, the increase was transient and subsided on POD 3. Levels of oxy-Hb and oxidized Cyt.aa3 in group 2 were significantly decreased when parenchymal disorder was confirmed histologically (POD 6 and 8), compared with those in group 1, which remained constant (P < 0.05). In group 3, both of these levels showed improvement. Thus, our NIR spectroscopy technique was shown to be capable of assessing simultaneously both the immune response and the degree of immune-induced destruction of allograft tissue following liver transplantation through monitoring of NO synthesis and tissue oxygenation.
Ohdan
H
H
Second Department of Surgery, Hiroshima University School of Medicine, Japan.
Fukuda
Y
Y
Suzuki
S
S
Amemiya
H
H
Dohi
K
K
D000818:Animals; D006084:Graft Rejection; D006454:Hemoglobins / Q000378:metabolism; D008099:Liver / Q000098:blood supply; D016031:Liver Transplantation / Q000276:immunology*; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000097:blood; D009926:Organ Preservation; D010084:Oxidation-Reduction; D010108:Oxyhemoglobins / Q000378:metabolism; D051381:Rats; D011912:Rats, Inbred ACI; D011917:Rats, Inbred Lew; D013055:Spectrophotometry, Infrared; D013997:Time Factors
D006454:Hemoglobins; D009573:Nitrites; D010108:Oxyhemoglobins; D009569:Nitric Oxide