In vivo ESR-CT imaging of the liver in mice receiving subcutaneous injection of nitric oxide-bound iron complex.

ESR measurements and ESR-CT imaging of subcutaneously (SC) injected nitric oxide (NO)-bound iron complexes were conducted on the upper abdomen of live mice. The use of NO-bound iron complex with N-(dithiocarboxy)sarcosine resulted in a clear ESR-CT image showing high intensity areas in the ventral regions, while other NO-bound iron complexes with N-methyl-D-glucamine dithiocarbamate or N,N-diethyl-dithiocarbamate were inappropriate because of low S/N ratios. To investigate the distributions of SC injected NO-bound iron complexes in the abdomens of mice, we measured ESR signals in resected abdominal organs. The signal amplitude was higher in the resected liver than in the resected gastrointestinal organs or the blood samples. The findings suggest that the high intensity areas in the ESR-CT images thus obtained correspond to the liver.