THE METABOLISM OF ³H-CURCUMOL IN NORMAL RATS AND TUMOUR BEARING MICE

Absorption of ³H-Curcumol from gastrointestinal tract in rats was rapid and complete. Radioactivity could be detected from the blood 5 minutes after oral administration, and reached its peak level within 15 minutes. The blood level declined gradually with a half life (t 1/2 β) of 11.5 hrs. After iv injection of ³H-curcumol, the blood level of radioactivity was found to decrease in two phases with half lives of 33 rain. (t 1/2 α) and 12.5 hrs. (t 1/2 β) respectively.Tissue distribution study in rats revealed that the radioactivity was more or less evenly distributed in various organs including the heart, muscle, lung, plasma, brain, testis and spleen except for the liver and kidney which contained radioactivity 2～2.5 times higher. The tissue concentration decreased in a rate similar to that of the blood, with the exception of the adipose tissue which seemed to have a tendency to keep the radioactivity in a constant level for over 4 hrs. The pattern of tissue distribution of ³H-curcumol in turnout bearing mice was similar to that in normal rats, and the concentration in turnout tissue was found to be similar to that in other tissues.Kidney seemed to be the main route of clearance. About 45.38% or 50.91% of the dose could be recovered in urine 24 hrs, after oral or iv administration. Biliary tract was another route of excretion. Twenty four hrs after oral or iv administration, about 36.47% or 56.43%, respectively, of the dose were recovered from the bile collected from the biliary fistula. However, the amount excreted in faeces constituted only 6.77% or 14.35% of the dose even 72 hrs after its oral or iv administration, suggesting that most of the radioactivity excreted from the bile was reabsorbed from the gastrointestinal tract in the intact animals.