ABSENCE OF C-TYPE NATRIURETIC PEPTIDE RECEPTORS IN HAMSTER GLOMERULI

Citation
Jkh. Luk et al., ABSENCE OF C-TYPE NATRIURETIC PEPTIDE RECEPTORS IN HAMSTER GLOMERULI, Nephron, 67(2), 1994, pp. 226-230
Citations number
23
Categorie Soggetti
Urology & Nephrology
Journal title
ISSN journal
00282766
Volume
67
Issue
2
Year of publication
1994
Pages
226 - 230
Database
ISI
SICI code
0028-2766(1994)67:2<226:AOCNPR>2.0.ZU;2-D
Abstract
The distribution of atrial natriuretic peptide receptor B (ANPR-B) var ies between tissues and species. The aim of this study is to determine whether ANPR-B is present in the hamster glomeruli. In vitro C-type n atriuretic peptide (CNP)and atrial natriuretic factor (ANF)-stimulated cGMP accumulation studies were performed in hamster glomeruli. Elevat ed cGMP accumulations were observed upon ANF addition. No cGMP respons e was seen with CNP. Competitive receptor-binding experiments were per formed with I-125-CNP and I-125-ANF against their respective cold pept ides in hamster glomeruli. Although no CNP binding was detected, posit ive ANF binding was found and two types of ANF receptor were demonstra ted. The affinity (K-dl) and maximum binding capacity (B-maxl) of the high-affinity ANF receptor were 0.014 +/- 0.001 nM and 60.4 +/- 10.2 f mol/mg protein, respectively. Those of the low-affinity receptor (K-d2 and B-max2) were 45.7 +/- 6.2 nM and 28.3 +/- 6.3 pmol/mg protein, re spectively. Similarly, saturation binding experiments also failed to s how any CNP receptor binding in hamster glomeruli. This finding sugges ts that ANPR-B is not present in hamster glomeruli and CNP is not a di rect physiological regulator of hamster renal function.