Whole body autoradiography of 5-fluorouracil-6-14C in nude mice bearing murine leukemia cells P388.

Whole body autoradiography of 5-fluorouracil (5-FU)-6-14C intraperitoneally injected to nude mice bearing murine leukemia cells (P388) indicated that absorption of 5-FU from mesenterium to digestive gland and canals was so quick that liver and stomach as well as duodenum had intensive radioactivity as 10 and 30 min after administration. Lower intestine had less radioactivity than duodenum and it was reduced noticeably as time passed. The activity in the kidney at initial stage was distributed throughout the cortex but it was concentrated to transitional zone between cortex and outer medulla at h stage. Lung had moderate activity throughout this experiment. Muscles and central nervous system had little radioactivity. Bone appeared radioactive to some extent. Interestingly, heart and cross section of blood vessels in liver and kidney had not radioactivity indicating that 5-FU was not retained in circulating system. These results were compared with that of uracil-14C and 5-fluorouracil-2-14C described by others.