Tumor accumulation of D-selenomethionine-75Se in tumor-bearing mice.
The radioactivity distribution of 75Se-labeled D-selenomethionine (D-SeMet-75Se) was investigated in tumor-bearing mice in order to develop a new radioactive diagnostic agent. D-SeMet-75Se was enzymatically prepared from commercially available L-selenomethionine-75Se (L-SeMet-75Se) by using amino acid racemase and immobilized L-amino acid oxidase. No difference between D- and L-SeMet-75Se was found in the excretion rate into urine and feces in normal mice within 48 h after administration. The in vivo uptake of D-SeMet-75Se in both Ehrlich solid tumor and sarcoma-180 solid tumor was several times higher than that of L-SeMet-75Se but the uptake of D- and L-SeMet-75Se were similar in the pancreas. These results indicated that D-SeMet-75Se might be useful as a tumor-imaging agent. In vitro experiments on Ehrlich ascites tumor cells showed that D-SeMet-75Se was incorporated into the tumor cells by a Na+-dependent active transport system similar to L-SeMet-75Se and that a transport mechanism specific for D-SeMet-75Se might be present in tumor cells in addition to a transport system common to both D- and L-forms.
Department of Radiobiochemistry, Shizuoka College of Pharmacy, Japan.
R
R
Goto
K
K
Unno
A
A
Takeda
S
S
Okada
O
O
Tamemasa
D019297:2,4-Dinitrophenol; D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000000981:diagnostic imaging; D002478:Cells, Cultured; D004140:Dinitrophenols / Q000494:pharmacology; D005243:Feces / Q000032:analysis; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011877:Radionuclide Imaging; D012510:Sarcoma 180 / Q000000981:diagnostic imaging; D012643:Selenium; D012644:Selenium Radioisotopes; D012645:Selenomethionine; D013237:Stereoisomerism
D004140:Dinitrophenols; D012644:Selenium Radioisotopes; D010042:Ouabain; D012645:Selenomethionine; D012643:Selenium; D019297:2,4-Dinitrophenol