Abstract
The effect of intraperitoneal injection of N1-(2'-tetrahydrofuryl)-5-fluorouracil (FT-207) which is metabolized to 5-fluorouracil (5-FU) in vivo, on endogenous colony forming units in the spleen (endogenous CFU-s) was observed and compared with that of 5-FU. The 8×10-4 m eqv of FT-207 injected in mice 20 minutes before X-rays irradiation of 450 rads suppressed the endogenous CFU-s count to about 60% and about 5.5×10-5 m eqv of 5-FU had the same effect. The suppression of FT-207 continued over 120 minutes and increased gradually. The effect of 5-FU was strong shortly after the injection but faded out for 120 minutes. FT-207 had almost no effect on the recovery constant (Blair) of endogenous CFU-s for 3 days, whereas 5-FU reduced seriously, especially for the first 2 days. The differences in the effects of both compounds could not be explained on the base of the only differences in the metabolism of both compounds.
