[Experimental studies on the enhancing effects of the combined therapy with tegafur and cytochrome C]

Coadministration of Tegafur and cytochrome C produced higher concentration of an active substance, 5-FU, in the blood of normal rats as compared with Tegafur alone. However, there was no difference between the combination regimen and Tegafur alone in LD50. Blood and tumor levels of 5-FU in tumor-bearing rats were higher in the combination than Tegafur alone, and survival effects were more favorable in the former. On the other hand, cytochrome C prohibited decrease in the amount of liver P-450 induced by carbon tetrachloride.