scholarly journals Roles of Vasopressin and Hypertonicity in Basolateral Na/K/2Cl Cotransporter Expression in Rat Kidney Inner Medullary Collecting Duct Cells.

1999 ◽  
Vol 49 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Naohiko ANZAI ◽  
Ibuki IZUMIDA ◽  
Yutaka KOBAYASHI ◽  
Katsumasa KAWAHARA
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct

Heat stress protein-associated cytoprotection of inner medullary collecting duct cells from rat kidney

1993 ◽  
Vol 265 (3) ◽  
pp. F333-F341 ◽  
Author(s):  
S. C. Borkan ◽  
A. Emami ◽  
J. H. Schwartz
Keyword(s):  
Heat Stress ◽  
Thermal Injury ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Metabolic Effects ◽  
Lactate Dehydrogenase Activity ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct

Although heat stress proteins (HSPs) mediate thermotolerance, the cellular targets of thermal injury and mechanisms of acquired cytoprotection are unknown. To describe the metabolic effects of hyperthermia and the potential mechanisms of thermotolerance, the following were measured in inner medullary collecting duct cells after a 43 degrees C and/or a 50 degrees C thermal insult: 1) state III mitochondrial respiration (SIII MR), 2) glycolytic rate, 3) lactate dehydrogenase activity, 4) membrane permeability, and 5) HSP 72 content. Compared with controls incubated at 37 degrees C, cells heated to 50 degrees C showed a 30 and 50% reduction in glycolysis and SIII MR, respectively. After heating to 50 degrees C, the cell membrane remained intact and immunoreactive HSP 72 was not detected. In contrast, heating to 43 degrees C induced accumulation of HSP 72 and transiently increased both SIII MR and glycolysis. In addition, prior exposure to 43 degrees C completely prevented the fall in SIII MR and glycolysis anticipated with a subsequent 50 degrees C insult. Cytoprotection gradually diminished over several days and correlated with the disappearance of HSP 72. Preservation of oxidative and anaerobic metabolism associated with HSPs may be important in developing resistance to thermal injury.

scholarly journals Transcriptional profiling of native inner medullary collecting duct cells from rat kidney

2008 ◽  
Vol 32 (2) ◽  
pp. 229-253 ◽  
Author(s):  
Panapat Uawithya ◽  
Trairak Pisitkun ◽  
Brian E. Ruttenberg ◽  
Mark A. Knepper
Keyword(s):  
Signal Intensity ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Transcriptional Profiling ◽  
High Signal ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct ◽  
V2 Vasopressin Receptor

Vasopressin acts on the inner medullary collecting duct (IMCD) in the kidney to regulate water and urea transport. To obtain a “parts list” of gene products expressed in the IMCD, we carried out mRNA profiling of freshly isolated rat IMCD cells using Affymetrix Rat 230 2.0 microarrays with ∼31,000 features; 7,913 annotated transcripts were found to be expressed above background in the IMCD cells. We have created a new online database (the “IMCD Transcriptome Database;” http://dir.nhlbi.nih.gov/papers/lkem/imcdtr/ ) to make the results publicly accessible. Among the 30 transcripts with the greatest signals on the arrays were 3 water channels: aquaporin-2, aquaporin-3, and aquaporin-4, all of which have been reported to be targets for regulation by vasopressin. In addition, the transcript with the greatest signal among members of the solute carrier family of genes was the UT-A urea transporter ( Slc14a2), which is also regulated by vasopressin. The V2 vasopressin receptor was strongly expressed, but the V1a and V1b vasopressin receptors did not produce signals above background. Among the 200 protein kinases expressed, the serum-glucocorticoid-regulated kinase ( Sgk1) had the greatest signal intensity in the IMCD. WNK1 and WNK4 were also expressed in the IMCD with a relatively high signal intensity, as was protein kinase A (β-catalytic subunit). In addition, a large number of transcripts corresponding to A kinase anchoring proteins and 14-3-3 proteins (phospho-S/T-binding proteins) were expressed. Altogether, the results combine with proteomics studies of the IMCD to provide a framework for modeling complex interaction networks responsible for vasopressin action in collecting duct cells.

19-Nordeoxycorticosterone synthesis by rat kidney inner medullary collecting duct cells

Steroids ◽  
1991 ◽  
Vol 56 (12) ◽  
pp. 578-580
Author(s):  
Sami T. Azar ◽  
James C. Melby ◽  
Thomas E. Wilson ◽  
Richard Nichols ◽  
John H. Schwartz
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct

Extracellular pH affects phosphorylation and intracellular trafficking of AQP2 in inner medullary collecting duct cells

2015 ◽  
Vol 308 (7) ◽  
pp. F737-F748 ◽  
Author(s):  
Hyo-Jung Choi ◽  
Hyun Jun Jung ◽  
Tae-Hwan Kwon
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Surface Expression ◽  
Extracellular Ph ◽  
Inner Medullary Collecting Duct ◽  
Duct Cells ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct

Kidney collecting duct cells are continuously exposed to the changes of extracellular pH (pHe). We aimed to study the effects of altered pHe on desmopressin (dDAVP)-induced phosphorylation (Ser256, Ser261, Ser264, and Ser269) and apical targeting of aquaporin-2 (AQP2) in rat kidney inner medullary collecting duct (IMCD) cells. When freshly prepared IMCD tubule suspensions exposed to HEPES buffer with pH 5.4, 6.4, 7.4, or 8.4 for 1 h were stimulated with dDAVP (10−10 M, 3 min), AQP2 phosphorylation at Ser256, Ser264, and Ser269 was significantly attenuated under acidic conditions. Next, IMCD cells primary cultured in transwell chambers were exposed to a transepithelial pH gradient for 1 h (apical pH 6.4, 7.4, or 8.4 vs. basolateral pH 7.4 and vice versa). Immunocytochemistry and cell surface biotinylation assay revealed that exposure to either apical pH 6.4 or basolateral pH 6.4 for 1 h was associated with decreased dDAVP (10−9 M, 15 min, basolateral)-induced apical targeting of AQP2 and surface expression of AQP2. Fluorescence resonance energy transfer analysis revealed that the dDAVP (10−9 M)-induced increase of PKA activity was significantly attenuated when LLC-PK1 cells were exposed to pHe 6.4 compared with pHe 7.4 and 8.4. In contrast, forskolin (10−7 M)-induced PKA activation and dDAVP (10−9 M)-induced increases of intracellular Ca2+ were not affected. Taken together, dDAVP-induced phosphorylation and apical targeting of AQP2 are attenuated in IMCD cells under acidic pHe, likely via an inhibition of vasopressin V2 receptor-G protein-cAMP-PKA actions.

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