A novel, selective radioligand, [125I]-[Lys5,Tyr(I2)7,MeLeu9,Nle10]-NKA(4-10), for the tachykinin NK-2 receptor.
A new radioligand, [125I]-[Lys5,Tyr(I2)7,MeLeu9,Nle10]-NKA(4-10), based on the selective agonist [Lys5,MeLeu9,Nle10]-NKA(4-10) has been developed. Binding in rat fundus membranes was displaced by NP gamma > NKA > or = [Lys5,MeLeu9,Nle10]-NK(4-10) > neuropeptide K > [Lys5,Tyr(I2)7,MeLeu9,Nle10]-NKA(4-10) > SP > [Sar9,Met(O2)11]-SP >> senktide, indicating binding to NK-2 receptors. Preliminary studies demonstrated high specific binding in membranes from rat urinary bladder, duodenum and colon. Specific binding in rat brain and lung was negligible, and binding in a range of guinea-pig tissues was no more than 35% specific. These data may indicate species differences in NK-2 receptors.
Badgery-Parker
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School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia.
Zeng
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Lavielle
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Burcher
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D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism*; D005748:Gastric Fundus / Q000378:metabolism; D006168:Guinea Pigs; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D015288:Neurokinin A / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism*; D009928:Organ Specificity; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D018041:Receptors, Neurokinin-2 / Q000032:analysis* / Q000378:metabolism
D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D018041:Receptors, Neurokinin-2; C080627:neurokinin A (4-10), Lys(5)-Tyr(I2)(7)-MeLeu(9)-Nle(10)-; D015288:Neurokinin A