[125I]Ifenprodil: a convenient radioligand for binding and autoradiographic studies of the polyamine-sensitive site of the NMDA receptor.
Iodination of ifenprodil, a non-competitive NMDA antagonist, with Na125I/Chloramin-T gave a radioligand which bound rapidly and saturably to a single population of sites (dissociation constant 145 nM) in membranes of rat cerebral cortex. In competition studies, specific binding of [125I]-ifenprodil was inhibited by analogues of ifenprodil, as well as by spermine and spermidine. Binding was sensitive to Ca2+, Mg2+ and Zn2+. [125I]-Ifenprodil labelled a population of binding sites, which was topographically distributed in rat forebrain, as shown by autoradiography. [125I]Ifenprodil is a useful radioligand for the investigation of the polyamine site of the N-methyl-D-aspartate (NMDA) receptor-complex.
Beart
P M
PM
University of Melbourne, Clinical Pharmacology and Therapeutics Unit, Austin Hospital, Heidelberg, Vic. Australia.
Mercer
L D
LD
Jarrott
B
B
D000818:Animals; D001345:Autoradiography; D015317:Biogenic Polyamines / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D008274:Magnesium / Q000494:pharmacology; D010880:Piperidines / Q000138:chemical synthesis; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects*; D013095:Spermidine / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
D015317:Biogenic Polyamines; D007457:Iodine Radioisotopes; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; D008274:Magnesium; D015032:Zinc; C010739:ifenprodil; D002118:Calcium; D013095:Spermidine