[Experimental study of the combined effect of 5-fluorouracil and cyclophosphane on growth of Zajdela hepatoma and nucleic acid metabolism].

Zajdela's ascites hepatoma of rats was treated with diverse combinations of 5-fluorouracil (5-FU) and cyclophosphane to study antitumour effect and the intensity of inhibiting the synthesis of nucleic acids. It was established that administration of 5-FU during the first three days and CP during the next three days in doses producing no effect when the drugs are given alone leads to an abrupt inhibition of tumour growth with concurrent inhibition of the synthesis of DNA and all fractions of total RNA. Administration of the drugs in the same succession but in higher doses that produce an inhibition of tumour growth (when the drugs are given alone) results in an antitumour action without eliciting pronounced side effect on bone marrow hemopoiesis.