HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kahana, L. Articles by Lurie, A. Search for Related Content PubMed Articles by Kahana, L. Articles by Lurie, A.

Identification and quantification of human kidney atrial natriuretic peptide receptors

Kahana L, Yechiely H, Mecz Y, Lurie A. Identification and quantification of human atrial natriuretic peptide receptors. Eur J Endocrinol 1995;132:465–71. ISSB 0804–4643

The present study determined ¹²⁵I-label atrial natriuretic peptide (ANP) binding sites in human kidney glomerular and papillary membranes. The membranes were prepared from non-malignant renal tissue obtained at nephrectomy of patients with renal carcinoma. To evaluate the proportion of ANP receptor classes ANP-R1 (ANPR-A, -B) versus ANP-R2 (ANPR-C), competitive binding studies were performed using [¹²⁵I]-ANP in the presence of increasing concentrations of ANP or an internally ring-deleted analog, des(Gln¹¹⁶, Ser¹¹⁷, Gly¹¹⁸, Leu¹¹⁹, Gly¹²⁰)ANP(102–121), called C-ANP, which binds selectively to ANPR-C receptors. Analysis of the competitive binding curve with ANP in glomerular membranes suggested the presence of one group of high-affinity receptors with dissociation constant K_d = 26 ± 12 pmol/l and density B_max = 101 ± 47 nmol/kg protein. A decrease of 10–30% in Bmax with no change in K_d was obtained in the presence of excess (10^–6 mol/l) C-ANP, suggesting the existence of a small amount of a second class of receptors, the ANPR-C class. The densities of ANPR-A, -B versus ANPR-C receptors in human glomeruli, calculated from competitive inhibition experiments, were 75 ± 42 and 22 ± 16 nmol/kg protein (N = 8). Autoradiography of the sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions showed two bands: a highly labeled 130kD band and a weakly labeled 66kD band, both displaced by ANP. Only the 66-kD band was displaced by the C-ANP analog. Human papilla membrane, as shown by competition binding studies and SDS gel electrophoresis, presented only one class of receptors with K_d = 40 ± 23 pmol/l (mean ± SD, N = 3) and B_max = 17 ± 6.3 nmol/kg protein. No displacement of [¹²⁵I]ANP with C-ANP analog could be detected. The K_d of the binding sites in human kidney papilla was not statistically different (p > 0.05) from the K_d values of the two receptor subtypes for ANP in glomeruli. Thus, human kidney, much like that of the rat, presents: two classes, the high- (ANPR-A, -B) and low (ANPR-C)-molecular-weight receptors, in glomerular membranes; only one class, the high-molecularweight receptors, in papillary membranes. In contrast to rat kidney, the high-molecular-weight ANPR-A, -B is the dominant class in human glomerular membranes.

Luna Kahana, Endocrine Laboratory, Carmel Medical Center, 7 Michal Street, Haifa 34362, Israel

This article has been cited by other articles:

				C. Sengenes, A. Zakaroff-Girard, A. Moulin, M. Berlan, A. Bouloumie, M. Lafontan, and J. Galitzky Natriuretic peptide-dependent lipolysis in fat cells is a primate specificity Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2002; 283(1): R257 - R265. [Abstract] [Full Text] [PDF]