Therapeutic effects of S-35-thiouracil in BALB/c mice carrying Harding-Passey melanoma.
Thiouracil (TU) selectively binds to the pigment melanin during melanogenesis and is rapidly cleared from normal tissues. This compound shows little affinity for pre-formed melanin. BALB/c mice, carrying the subcutaneously transplanted Harding-Passey melanoma, were given i.p. injections of 35S-labeled thiouracil in a range of doses and administration schedules. Injected doses ranged from 1.3 to 10 mCi per mouse with resultant tumor dose rates of 10 to 30 cGy/hr, respectively. At the lower dose rates, growth delay of approximately 1 to 2 weeks was observed in all tumors. At the highest doses used, complete tumor regression (no regrowth) was observed in some cases, with extended growth delays of approximately 6 weeks in the rest. These results illustrate the possible utility of radiolabeled thiouracil as a systemically administered brachytherapy agent for melanoma.
Fairchild
R G
RG
Medical Department, Brookhaven National Laboratory, Upton, NY 11973.
Coderre
J A
JA
Packer
S
S
Greenberg
D
D
Laster
B H
BH
D000818:Animals; D001918:Brachytherapy / Q000379:methods*; D008546:Melanoma, Experimental / Q000378:metabolism / Q000532:radiotherapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D013462:Sulfur Radioisotopes / Q000627:therapeutic use*; D013889:Thiouracil / Q000493:pharmacokinetics*
D013462:Sulfur Radioisotopes; D013889:Thiouracil