title: Modulation of the effects of fluoropyrimidines on toxicity and tumor inhibition in rodents by uridine and thymidine.
abstract: Uridine and/or thymidine were administered concomitantly with 5-fluorouracil (5-FU) and 5'-deoxy-5-fluorouridine (5'-dFUR) to mice and rats in order to establish whether the physiological nucleosides acting in vitro as antagonists can diminish fluoropyrimidine toxicity in vivo. In addition, the influence of orally co-administered uridine on antitumor activity of 5-FU and 5'-dFUR in mice has been studied. All co-administrations aggravated the general toxicity of both fluoropyrimidines. Tumor inhibition was enhanced by uridine, but the therapeutic ratio was not improved compared to monotherapy with either 5-FU or 5'-dFUR.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005467:Floxuridine / Q000627:therapeutic use / Q000633:toxicity*; D005472:Fluorouracil / Q000627:therapeutic use / Q000633:toxicity*; D007939:Leukemia L1210 / Q000188:drug therapy*; D008175:Lung Neoplasms / Q000188:drug therapy*; D008297:Male; D051379:Mice; D051381:Rats; D011919:Rats, Inbred Strains; D012510:Sarcoma 180 / Q000188:drug therapy*; D013936:Thymidine / Q000494:pharmacology* / Q000627:therapeutic use; D014529:Uridine / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D005467:Floxuridine; D005472:Fluorouracil; D013936:Thymidine; D014529:Uridine