Metabolism of tegafur in rat liver observed by in vivo 19F magnetic resonance spectroscopy and chromatography.

Metabolism of tegafur in the rat liver was observed by in-vivo 19F magnetic resonance spectroscopy (MRS). After MRS observation, tegafur and q-fluorouracil (5-FU) in the liver were determined by a chromatographic method for comparison with the results of 19F-MRS. Rats were divided into 3 groups: 1) CCl4-induced liver injury group, 2) uracil combined group, 3) control group. Catabolism to fluoro-beta-alanine was suppressed in both the liver injury group and the uracil combined group. Low peaks of 5-FU and fluoronucleotides could be found only in the uracil combined group. The result of 19F MRS observation of each group was in agreement with the result of determination of tegafur and 5-FU by chromatography. This showed that substances which could be observed by 19F-MRS were in proportion to all intracellular fluoro-containing substances. 19F-MRS can provide direct information on the metabolism of fluoropyimidines non-invasively and it might be a useful aid in choosing suitable chemotherapy for patients.