TY - JOUR
T1 - Regulation of (3h) arginine8 vasopressin binding to the rat renal medulla by guanine nucleotides
AU - Cornett, Lawrence E.
AU - Dorsa, Daniel M.
N1 - Funding Information:
We thank Ms. Ywmne Rodriguez for secretarial assistance in preparing this manuscript and Ms. Rena &mey and Ms. Stephanie Breckenridge for technical assistance. This work was supported in part by National Institutes of Health Grants AM 34507 and NS 20311, an University of Arkansas for Medical Sciences Institutional Grant and the Veterans Administration.
PY - 1986
Y1 - 1986
N2 - In rat renal medullary membranes, we have examined modulatory effects of guanine nucleotides on binding of arginine vasopressin (AVP) to its receptor. Equilibrium binding studies analyzed by an iterative curve fitting program revealed an interaction of (3H) AVP with a single class of binding sites with a dissociation constant of 1.4±0.2 nM and a binding site concentration of 201±37 fmol/mg protein (n=6). With the addition of 100 μM guanylyl-imidodiphosphate (Gpp(NH)p), the binding site concentration was significantly (p < 0.01) reduced to 151±36 fmol/mg protein with no change in receptor affinity. The nonhydrolyzable analogues, guanosine-53′O-(3-thiophosphate) and Gpp(NH)p were the most potent inhibitors of (3H) AVP binding. Guanosine 5′triphoshate and guanosine-5′diphosphate were both relatively poor inhibitors. Guanosine-5′monophosphate and adenosine 5′triphosphate did not inhibit (3H) AVP binding at concentrations up to 100 μM. Furthermore, 100 μM Gpp(NH)p accelerated the dissociation of (3H) AVP from the receptor. We conclude that guanine nucleotides are important modulators of AVP binding to the V2 receptor subtype in the renal medulla.
AB - In rat renal medullary membranes, we have examined modulatory effects of guanine nucleotides on binding of arginine vasopressin (AVP) to its receptor. Equilibrium binding studies analyzed by an iterative curve fitting program revealed an interaction of (3H) AVP with a single class of binding sites with a dissociation constant of 1.4±0.2 nM and a binding site concentration of 201±37 fmol/mg protein (n=6). With the addition of 100 μM guanylyl-imidodiphosphate (Gpp(NH)p), the binding site concentration was significantly (p < 0.01) reduced to 151±36 fmol/mg protein with no change in receptor affinity. The nonhydrolyzable analogues, guanosine-53′O-(3-thiophosphate) and Gpp(NH)p were the most potent inhibitors of (3H) AVP binding. Guanosine 5′triphoshate and guanosine-5′diphosphate were both relatively poor inhibitors. Guanosine-5′monophosphate and adenosine 5′triphosphate did not inhibit (3H) AVP binding at concentrations up to 100 μM. Furthermore, 100 μM Gpp(NH)p accelerated the dissociation of (3H) AVP from the receptor. We conclude that guanine nucleotides are important modulators of AVP binding to the V2 receptor subtype in the renal medulla.
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U2 - 10.3109/10799898609073928
DO - 10.3109/10799898609073928
M3 - Article
C2 - 3522888
AN - SCOPUS:0022555639
SN - 1079-9893
VL - 6
SP - 127
EP - 140
JO - Journal of Receptors and Signal Transduction
JF - Journal of Receptors and Signal Transduction
IS - 2
ER -