title: [3H]desGly-NH2(9)-d(CH2)5[D-Ileu2,Ileu4]AVP: an AVP V2 receptor antagonist radioligand.
abstract: Binding characteristics of the selective V2 antagonist radioligand [3H]desGly-NH2(9)-d(CH2)5[D-Ileu2,Ileu4]AVP to rat kidney were determined. Binding was specific, saturable and reversible. The peptide bound to a single class of high-affinity binding sites with Bmax 69.4 +/- 6.8 fmol/mg protein and KD 2.8 +/- 0.3 nM. AVP and other related peptides displaced [3H]desGly-NH2(9)-d(CH2)5[D-Ileu2,Ileu4]AVP binding. The order of potency of inhibition was desamino-D-AVP greater than AVP greater than d(CH2)5[D-Ileu2,Ileu4]AVP greater than oxytocin greater than d(CH2)5[Tyr(Me)2]AVP greater than d(CH2)5[sarcosine7]AVP, which is typical of a selective V2 radioligand. Autoradiographic localization of [3H]desGly-NH2(9)-d(CH2)5[D-Ileu2,Ileu4]AVP binding sites in kidney showed dense binding in the inner and outer medulla with less binding in the cortex, which is consistent with known renal V2 receptor distribution.
authors.affiliation: University of Melbourne, Department of Medicine, Austin Hospital, Heidelberg, Victoria, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Trinder
authors.forename: J M
authors.initials: JM
authors.lastname: Stephenson
authors.forename: X
authors.initials: X
authors.lastname: Gao
authors.forename: P A
authors.initials: PA
authors.lastname: Phillips
authors.forename: J
authors.initials: J
authors.lastname: Risvanis
authors.forename: C I
authors.initials: CI
authors.lastname: Johnston
mesh_terms: D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives* / Q000378:metabolism; D001345:Autoradiography; D066298:In Vitro Techniques; D007679:Kidney Medulla / Q000378:metabolism; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011945:Receptors, Angiotensin / Q000145:classification / Q000378:metabolism; D017483:Receptors, Vasopressin
chemical_list: D057911:Angiotensin Receptor Antagonists; D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; C070737:argipressin, beta mercapto(beta,beta)-cyclopentamethylenepropionic acid(1)-Ile(2,4)-Ala-NH2(9)-; D001127:Arginine Vasopressin