title: Preferential incorporation of some 14C-labeled D-amino acids into tumor-bearing animals.
abstract: In order to acquire a fundamental knowledge for the development of better tumor-scanning agents, the in vivo incorporation pattern of three 14C-labeled D-amino acids, alanine, leucine, and tryptophan, into the tumor cells and organs of animals bearing Ehrlich mouse tumor, sarcoma-180, leukemia L-1210, or Yoshida sarcoma was investigated, and compared with that of the corresponding L-forms. The radioactivity of D-amino acids tested was most highly found in tumor cells and pancreas, and the activity in tumor cells was several times higher than that of L-forms. A large portion of the radioactivity of D-forms was found in trichloroacetic acid-soluble fraction of the cells, whereas that of L-forms was mostly in protein fraction, except L-alanine. Although the mechanisms whereby the radioactivity of D-amino acids was concentrated more than that of L-forms in the tumor cells have not yet been clearly elucidated, it was concluded that gamma-emitter-labeled D-amino acids themselves or their derivatives might be useful as tumor-detecting radiopharmaceuticals.
mesh_terms: D000409:Alanine / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D007939:Leukemia L1210 / Q000378:metabolism; D008297:Male; D051379:Mice; D009374:Neoplasms, Experimental / Q000378:metabolism*; D010179:Pancreas / Q000378:metabolism; D012510:Sarcoma 180 / Q000378:metabolism; D012517:Sarcoma, Yoshida / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002250:Carbon Radioisotopes; D007930:Leucine; D000409:Alanine