Radiosynthesis and Biodistribution of 99mTc-Trimethoprim: A NovelRadiolabeled Antibiotic for Bacterial Infection Imaging UsingExperimental Animals

Turkish

In the present article, we focused on the radiolabeling and evaluation of 99m Tc-TMH complex as a potential candidate for infection imaging in vivo. For this; Trimethoprim (TMH) used to treat bacterial infections was investigated to label with 99m Tc. Labeling was performed using thin (II) chloride as a reducing agent at room temperature for 1 h and radiochemical analysis involved thin layer radiochromatography (TLRC) and high pressure liquid radiochromatograpy (HPLRC) methods. The stability of labeled antibiotic was checked in the presence of rat blood serum at 37 C up to 180 min. The maximum radiolabeling yield was found to be 962% and remained constant at more than 851% even in rat serum for 180 min after radiolabeling. Static image of 99m Tc-TMH in male rats demonstrated that important radiation signals are present in the infected site at first glance in 30 min. After 30 min the uptake of the 99m Tc-TMH as ID/g% in the infected muscle (INM) and normal muscle (NM) of the rats were 7.51.5% and 5.001.2%, respectively. In the INM/NM ratio a desirable behavior was observed as the values for the INM/ NM increased up to 10.6. 99m Tc-TMH prepared with high yield is able to localize well in the bacterially infected muscle of the rats. As a result, 99m Tc-TMH may be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging.