Radiosensitizing activity and metabolism of some nitrofuran preparations

It was shown that the preparation of a nitrofuran M-106 series exerts a radiosensitizing effect on tumors with contact application. The observed effect is practically absent after noncontact administration of the preparation. On the basis of the data obtained from studies of M-106 metabolism in microsomes of liver and Ehrlich ascites tumor cells of mice it is concluded that the intact form of the preparation is responsible for the radiosenstizing effect, and that the absence of this effect with the noncontact administration is due to its low concentration in the tumor because of the active metabolic transformation of M-106 in the animal liver