Binding of [125I]Bolton Hunter conjugated eledoisin to rat brain cortex membranes--evidence for two classes of tachykinin receptors in the mammalian central nervous system.

[125I]Bolton Hunter conjugated eledoisin was prepared and purified by ion-paired reverse phase chromatography. The ligand binds to rat brain cortex membranes, and the binding is inhibited over 95% by unlabeled eledoisin (6.6 microM). The binding site appears to be distinct from the [125I]Bolton Hunter conjugated substance P receptor based on the relative potencies of substance P, eledoisin, kassinin, physalaemin and [pGlu]substance P (6-11) hexapeptide to displace the binding of these two ligands.