Abstract
With the intension of exploiting latent information in a continuous spectrum we constructed an in vivo nearinfrared spectroscopy system including multicomponent analysis. The progress of acute rejection inorthotopically transplanted rat liver was monitored with this system. In the course of this study we found thatnitrosylhemoglobin could be quantitated. The results revealed that increase of water content and decrease ofthe levels of oxyhemoglobin and oxidized form of cytochrome c oxidase, corresponding to edema and circulatoryfailure in revascularized graft, took place at an advaced stage of rejection. On the other hand, rapidincrease of nitrosylhemoglobin occured at the onset of the immune response, when any tissue damage was notbrought about. Treatment with an immunosuppressant depressed these events. We also studied elongation oflight path length due to multiple scattering in red blood cell suspensions and in a gerbil head under hypoxia.
