title: Atrial natriuretic peptide and nitric oxide signaling antagonizes vasopressin-mediated water permeability in inner medullary collecting duct cells.
abstract: AVP and atrial natriuretic peptide (ANP) have opposite effects in the kidney. AVP induces antidiuresis by insertion of aquaporin-2 (AQP2) water channels into the plasma membrane of collecting duct principal cells. ANP acts as a diuretic factor. An ANP- and nitric oxide (NO)/soluble guanylate cyclase (sGC)-induced insertion of AQP2 into the plasma membrane is reported from different models. However, functional data on the insertion of AQP2 is missing. We used primary cultured inner medullary collecting duct (IMCD) cells and digital holographic microscopy, calcein-quenching measurements, and immunofluorescence and Western blotting to analyze the effects of ANP and NO donors on AQP2 phosphorylation, membrane expression, and water permeability. While AVP led to acceleration in osmotically induced swelling, ANP had no effect. However, in AVP-pretreated cells ANP significantly decreased the kinetics of cell swelling. This effect was mimicked by 8-bromo-cGMP and blunted by PKG inhibition. Stimulation of the NO/sGC pathway or direct activation of sGC with BAY 58-2667 had similar effects to ANP. In cells treated with AVP, AQP2 was predominantly localized in the plasma membrane, and after additional incubation with ANP AQP2 was mostly localized in the cytosol, indicating an increased retrieval of AQP2 from the plasma membrane by ANP. Western blot analysis showed that ANP was able to reduce AVP-induced phosphorylation of AQP2 at position S256. In conclusion, we show that the diuretic action of ANP or NO in the IMCD involves a decreased localization of AQP2 in the plasma membrane which is mediated by cGMP and PKG.
authors: Medizinische Klinik und Poliklinik D, Experimentelle Nephrologie, Universitätsklinikum Münster, Münster, Germany.
authors: Jens
authors: J
authors: Klokkers
authors: Patrik
authors: P
authors: Langehanenberg
authors: Björn
authors: B
authors: Kemper
authors: Sebastian
authors: S
authors: Kosmeier
authors: Gert
authors: G
authors: von Bally
authors: Christoph
authors: C
authors: Riethmüller
authors: Frank
authors: F
authors: Wunder
authors: Aleksandra
authors: A
authors: Sindic
authors: Hermann
authors: H
authors: Pavenstädt
authors: Eberhard
authors: E
authors: Schlatter
authors: Bayram
authors: B
authors: Edemir
mesh_terms: D000818:Animals; D051399:Aquaporin 2 / Q000378:metabolism*; D001127:Arginine Vasopressin / Q000378:metabolism*; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D048429:Cell Size; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D004231:Diuresis; D005260:Female; D006162:Guanylate Cyclase / Q000378:metabolism; D007679:Kidney Medulla / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009997:Osmotic Pressure; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D000071756:Soluble Guanylyl Cyclase; D014867:Water / Q000378:metabolism*
chemical_list: C496025:Aqp2 protein, rat; D051399:Aquaporin 2; D020030:Nitric Oxide Donors; D018160:Receptors, Cytoplasmic and Nuclear; D014867:Water; D001127:Arginine Vasopressin; D009569:Nitric Oxide; D009320:Atrial Natriuretic Factor; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; D000071756:Soluble Guanylyl Cyclase; C091715:atrial natriuretic factor receptor A; D006152:Cyclic GMP