99mTc-labeled field bean protease inhibitor can function as an efficient tumor detecting agent.
Purified field bean protease inhibitor (FBPI) was labeled with 99mTcO4- to ascertain its ability to locate tumors in tumor-bearing rat models. The labeling was done with Sn2+ as a reducing agent and the yield was 95%. It was stable for 2 hr at ambient temperature. The biodistribution study of the intravenously injected radiolabeled FBPI in normal Wistar rats at various time intervals showed a rapid blood clearance from the systemic circulation (approximately 5hr). The complex was predominantly excreted through the renal and the hepatobiliary systems. In vivo distribution and scintiimaging of 99mTc-FBPI were carried out in rats bearing carcinogen-induced mammary tumor or transplanted C6-gliomas. The results obtained were compared with conventional tumor-seeking radiopharmaceuticals such as 99mTc-(V)dimercaptosuccinic acid (DMSA), 201Thallous chloride (TICI) and 99mTc-Citrate. The tumor to muscle (T/M) ratios obtained with 99mTc-FBPI in rat C6 glioma was nearly 2 to 5-fold higher than obtained with all the three conventional tumor-seeking agents. The T/M ratio obtained with 99mTc-FBPI in rat mammary tumor on the other hand appeared to be 2-3-fold higher than noted with 99mTc(V)-DMSA and 201TlCl. The ratio was however comparable with that obtained with 99mTc-Citrate. The study indicated that 99mTc-FBPI has the specific potentials for imaging gliomas and possibly other tumors as well.
Murugesan
S
S
Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Hospital Annexe, Parel, Mumbai, India. smuru1999@yahoo.com
Banerji
A P
AP
Noronha
O P
OP
Samuel
A M
AM
Fernandes
A O
AO
D000818:Animals; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D007887:Fabaceae / Q000737:chemistry*; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging*; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D011480:Protease Inhibitors / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D011480:Protease Inhibitors; D019275:Radiopharmaceuticals