TY - JOUR
T1 - [125i]-[d(CH2)5, sar7] AVP
T2 - A selective radioligand for v1 vasopressin receptors
AU - Kelly, J. M.
AU - Abrahams, J. M.
AU - Phillips, P. A.
AU - Mendelsohn, F. A.O.
AU - Grzonka, Z.
AU - Johnston, C. I.
PY - 1989
Y1 - 1989
N2 - Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, [1-(βmercapto-βbeta;cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine] vasopressin ([d(CH2)5, Sar7]AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd=3.0nM and Bmax=530±10 fmol/mg protein, kidney: Kd=0.5±0.9nM and Bmax=11±8 fmol/mg protein). Competition of [125I]-[d(CH2)5, Sar7]AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: [d(CH2)5, Tyr(Me)2]AVP > AVP > [d(CH2)5, D-Ile2, Ile4] AVP > DDAVP. No degradation of [125I]-[d(CH2)5, Sar7]AVP during incubation or storage was detected by HPLC analysis. We have used [125I]-[d(CH2)5, Sar7]AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that [125I]-[d(CH2)5, Sar7]AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.
AB - Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, [1-(βmercapto-βbeta;cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine] vasopressin ([d(CH2)5, Sar7]AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd=3.0nM and Bmax=530±10 fmol/mg protein, kidney: Kd=0.5±0.9nM and Bmax=11±8 fmol/mg protein). Competition of [125I]-[d(CH2)5, Sar7]AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: [d(CH2)5, Tyr(Me)2]AVP > AVP > [d(CH2)5, D-Ile2, Ile4] AVP > DDAVP. No degradation of [125I]-[d(CH2)5, Sar7]AVP during incubation or storage was detected by HPLC analysis. We have used [125I]-[d(CH2)5, Sar7]AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that [125I]-[d(CH2)5, Sar7]AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.
UR - http://www.scopus.com/inward/record.url?scp=0024477034&partnerID=8YFLogxK
U2 - 10.3109/10799898909066043
DO - 10.3109/10799898909066043
M3 - Article
C2 - 2521670
AN - SCOPUS:0024477034
VL - 9
SP - 27
EP - 41
JO - Journal of Receptors and Signal Transduction
JF - Journal of Receptors and Signal Transduction
SN - 1079-9893
IS - 1
ER -