[adenylate cyclase system in Ehrlich ascites tumor cells sensitive and resistant to 5-fluorouracil]

It is established that the adenylate cyclase activity in cells of the tumour strain resistant to 5-fluorouracil was higher and that of 3':5' AMP phosphodiesterase was lower as compared to the activity of these enzymes in cells of the tumor strain sensitive to the preparation. The cyclic AMP level in the resistant to 5-FU tumour cells was considerably higher than in cells of the sensitive tumour strain.