Histamine-indomethacin(HIS-IN) was labeled with 131I by chloramine-T method.Thin-layer chromatography(TLC) was performed to evaluate the labeling ratio

radiochemical purity and stability of 131I-HIS-IN

using silicagel GF254 coated on glass plates

with chloroform and methanol being the mobile phase.The biodistributions of 131I-HIS-IN in Lewis pulmonary tumor model mice and normal mice were examined

and therapeutic effect of 131I-HIS-IN on mice with Lewis pulmonary tumor was studied.The results showed that radiochemical purity of the 131I-HIS-IN was 98%

and the highest %ID.g–1 of tumor tissue was 4.73±0.07 at 4 h

while the tumor/blood ratios were 2.95±0.30 at 8 h

2.67±0.62 at 12 h and 3.54±0.54 at 16 h.The ratios

and the necrotic tissue cells

increased with the post-injection hours.Therefore

131I-HIS-IN can be a new radioactive drug for tumor therapy.