[I-125] SNF-8702 - A SELECTIVE RADIOLIGAND FOR CCKB RECEPTORS

The CCK-8 analogue, SNF 8702, was radioiodinated. [I-125]SNF 8702 show ed high-affinity specific binding for both guinea pig and mouse brain tissues, whereas no specific binding was seen for guinea pig pancreati c tissue. The properties of the site labeled by [I-125]SNF 8702 were c haracterized by binding inhibition studies for a series of CCKA and CC KB receptor ligands. The binding selectivity profile corresponded to t hat for the CCKB receptor. The labeled compound is stable for more tha n 6 weeks during storage at -20 degrees C.