title: Evaluation of radio- and chemotoxic effects of 125I-UdR on tumour growth and host survival.
abstract: The toxicity of 5-iodo-2'-deoxyuridine (I-UdR) was assayed in male C57 BL/6J mice bearing the syngeneic mammary adenocarcinoma EO 771 by injecting different doses of 'cold' I-UdR or 125-iodine labelled I-UdR. Host survival, tumour growth, DNA-precursor incorporation, whole-body retention and tumour activity loss rates were chosen as biological end points. There was no measurable effect on host survival up to doses of 5 micrograms I-UdR or 50 microCi 125I-UdR per mouse during a mean life-span of 25 days. Adjusted to a constant amount of 0.55 micrograms I-UdR/mouse, radiotoxicity of 125I-UdR on tumour growth (up to 17 days after implantation), tracer incorporation, whole-body and tumour retention (up to 12 days after 125I-UdR injection) could be excluded up to a dosage of 50 microCi 125I-UdR/mouse. It is concluded that in situ evaluation of tumour activity loss rates in carcinoma EO 771 is not disturbed by toxic effects of I-UdR or 125I-UdR within the dose limits mentioned.
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000532:radiotherapy*; D000818:Animals; D004273:DNA, Neoplasm / Q000378:metabolism / Q000528:radiation effects; D007065:Idoxuridine / Q000378:metabolism / Q000627:therapeutic use / Q000633:toxicity*; D007457:Iodine Radioisotopes / Q000627:therapeutic use / Q000633:toxicity*; D008297:Male; D008325:Mammary Neoplasms, Experimental; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D011836:Radiation Tolerance
chemical_list: D004273:DNA, Neoplasm; D007457:Iodine Radioisotopes; D007065:Idoxuridine