title: Stimulating effects of inosine, uridine and glutamine on the tissue distribution of radioactive D-leucine in tumor bearing mice.
abstract: This experiment was carried out in search for stimulators of the in vivo uptake of D- and L-leucine by tumor and pancreas for the possible application to gamma-emitter labeled amino acids in nuclear medical diagnosis. Inosine, uridine, and glutamine which are stimulators of the in vitro incorporation of radioactive L-amino acids into some tumor cells significantly enhanced the uptake of D-leucine into the pancreas, while in Ehrlich solid tumor only a little if any increase was observed. Of the compounds tested inosine showed the highest stimulation of pancreas uptake in the range of doses used, resulting in the best pancreas-to-liver concentration ratio, a factor of significant consideration for pancreas imaging. The uptake of L-leucine by the tumor and pancreas was little affected by these compounds.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes / Q000378:metabolism*; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D005973:Glutamine / Q000494:pharmacology*; D006801:Humans; D007288:Inosine / Q000494:pharmacology*; D007930:Leucine / Q000378:metabolism*; D051379:Mice; D010179:Pancreas / Q000378:metabolism; D013268:Stimulation, Chemical; D014529:Uridine / Q000494:pharmacology*
chemical_list: D002250:Carbon Radioisotopes; D005973:Glutamine; D007288:Inosine; D007930:Leucine; D014529:Uridine