title: [Biochemical differences in the tumor cells of 5-fluorouracil-sensitive and -resistant strains of Ehrlich ascitic carcinoma].
abstract: Essential differences have been disclosed as regards 5-FU-6-3H incorporation into RNA of tumor cells of Ehrlich's ascites carcinoma strains susceptible and resistant to 5-FU in vitro. In vivo the rate of drug incorporation into RNA of tumor cells was fairly high and noticeably varied depending on tumor cell susceptibility to 5-FU. At the same time the rate of drug incorporation into RNA of liver, spleen, kidney, and intestinal mucosa cells was negligible, thus attesting to a selective action of 5-FU on tumor cells. In tumor cells of Ehrlich's ascites carcinoma strain susceptible to 5-FU, adenylate cyclase activity was lower, whereas the activity of cAMP phosphodiesterase was higher than that in tumor cells of the carcinoma strain resistant to 5-FU. The content of cAMP in tumor cells of the 5-FU susceptible strain amounted to 2.54, that in tumor cells of the 5-FU resistant strain 7.63 pmol/mg protein.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D002478:Cells, Cultured; D004351:Drug Resistance; D005472:Fluorouracil / Q000378:metabolism*; D066298:In Vitro Techniques; D051379:Mice; D009368:Neoplasm Transplantation; D012334:RNA, Neoplasm / Q000378:metabolism; D012995:Solubility; D014018:Tissue Distribution
chemical_list: D012334:RNA, Neoplasm; D005472:Fluorouracil
vernacular_title: Biokhimicheskie razlichiia v opukholevykh kletkakh chuvstvitel'nogo i ustoĭchivogo k 5-ftoruratsilu shtammov astsitnoĭ kartsinomy Erlikha.