DISPOSITION OF DX-52-1, A NOVEL ANTICANCER AGENT, AFTER INTRAVENOUS ADMINISTRATION TO MICE AND DOGS

DX-52-1 is a new derivative of a quinocarmycin analogue. The dispositi on of [H-3]-DX-52-1 was investigated in mice and dogs after intravenou s administration (4 and 0.15 mg/kg, respectively). The plasma concentr ation of non-volatile radioactivity was 7.4 mu g eq./ml 3 min after ad ministration to mice, then declined biphasically until 2 h. The distri bution of non-volatile radioactivity into blood cells was 20% 3 min af ter administration, being maintained until 30 min. The plasma concentr ation of unchanged drug was almost equal to that of the radioactivity 3 min after administration and the unchanged drug ratio decreased rapi dly. High radioactivity was found in the gall bladder, kidney, liver, and lung 15 min after administration. No radioactivity was detected in most tissues 24 h post-administration. The cumulative excretion of to tal radioactivity into urine and feces after administration was 68 and 28% within 96 h, respectively. The plasma concentration of non-volati le radioactivity was 0.65 mu g eq./ml 3 min after administration to do gs. The distribution of non-volatile radioactivity into blood cells wa s about 20% 3 min after administration and this level tended to increa se with time. The cumulative excretion of total radioactivity into uri ne and feces after administration was 62 and 24%, respectively.