Cellular localization, membrane distribution, and possible function of guanylyl cyclases A and 1 in collecting ducts of rat.
Cardiovasc Res
; 51(3): 553-61, 2001 Aug 15.
Article
in En
| MEDLINE
| ID: mdl-11476745
ABSTRACT
BACKGROUND:
Natriuretic peptides regulate Na+ and H(2)O transport in the cortical collecting duct (CCD). We have shown that natriuretic peptides have no effect on ion conductances or water transport of principal cells (PC) even though a cGMP-regulated K+ channel is located in the basolateral membrane of these cells.METHODS:
RT-PCR was used to screen for different guanylyl cyclases (GC) in CCD and to look for the expression of GC-1 and GC-A mRNA in CCD of male and female Wistar and Sprague-Dawley rats. Polyclonal antibodies were raised against the detected GC. BCECF was used to investigate the effects of ANP on intracellular pH in intercalated cells (IC).RESULTS:
GC-A and GC-1 were detected. GC-A was immunolocalized in the luminal membrane of IC while GC-1 was mainly found in the luminal membrane of PC. GC-1 is expressed in Sprague-Dawley and Wistar rats except for male Sprague-Dawley rats, while GC-A is expressed in all strains. ANP (160 nM, n=11), urodilatin (140 nM, n=6), which had no effect in PC, significantly decreased pH(i) by 0.02+/-0.01 and 0.03 +/- 0.01 Units in IC, respectively. ANP as well as urodilatin and 8-Br-cGMP decreased the pH(i) recovery after acidification by 30 +/- 6% (n=12), 37 +/- 7% (n=8), and 19 +/- 3% (n=8), respectively.CONCLUSION:
GC-A is located in the luminal membrane of IC of rat CCD and ANP acts through this receptor when regulating pH(i) via an inhibition of the Na+/H+-exchanger. PC do not possess GC-A. GC-1 seems to be the only GC in these cells of most rat strains tested and therefore, it could be responsible for the regulation of K+ channels in the basolateral membrane via cGMP-dependent protein kinase.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Receptors, Atrial Natriuretic Factor
/
Guanylate Cyclase
/
Kidney Tubules, Collecting
Limits:
Animals
Language:
En
Journal:
Cardiovasc Res
Year:
2001
Document type:
Article