Lectin-gold labeling of glycoconjugates in normal and Brattleboro rat papilla: effect of vasopressin

1988 ◽  
Vol 254 (3) ◽  
pp. C450-C458 ◽  
Author(s):  
P. Weyer ◽  
D. Brown ◽  
L. Orci
Keyword(s):  
Epithelial Cell ◽  
Plasma Membranes ◽  
Collecting Duct ◽  
Helix Pomatia ◽  
Major Effect ◽  
Urinary Concentration ◽  
Brattleboro Rats ◽  
Cell Plasma ◽  
Collecting Ducts ◽  
Helix Pomatia Lectin

Some reports suggest that the plasma membrane glycocalyx of collecting duct epithelial cells, as well as interstitial glycoconjugates, may be involved in vasopressin action and urinary concentration. In view of this, we have used the lectin-gold technique to map and quantify Helix pomatia lectin (HPL)-binding sites in the inner medulla of kidneys from normal Long-Evans rats, vasopressin-deficient Brattleboro rats, and Brattleboro rats treated for up to 5 wk with exogenous vasopressin. The results show that the labeling of epithelial cell plasma membranes from collecting ducts and thin limbs of Henle is not different between normal and Brattleboro rats, and the labeling is not modified by chronic vasopressin treatment. In contrast, the heavy interstitial labeling seen in normal rats is virtually absent from Brattleboro rats, but it is progressively restored by chronic vasopressin treatment of Brattleboro rats. These results show that vasopressin does not modify HPL-binding glycoconjugates on epithelial cell plasma membranes, but that vasopressin treatment has a major effect on HPL-binding glycoconjugates in the medullary interstitium.

Lectin-gold cytochemistry reveals intercalated cell heterogeneity along rat kidney collecting ducts

1985 ◽  
Vol 248 (3) ◽  
pp. C348-C356 ◽  
Author(s):  
D. Brown ◽  
J. Roth ◽  
L. Orci
Keyword(s):  
Plasma Membranes ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Lectin Binding ◽  
Helix Pomatia ◽  
Intercalated Cells ◽  
Double Labeling ◽  
Thin Sections ◽  
Intercalated Cell ◽  
Collecting Ducts

The lectin-gold technique was used to detect Helix pomatia and Dolichos biflorus lectin binding sites directly on semithin and thin sections of rat kidney collecting ducts. Intercalated cell apical plasma membranes and the membranes of apical cytoplasmic vesicles were heavily labeled in the cortex and outer stripe of the outer medulla but were negative or very weakly labeled in the inner stripe and inner medulla. In contrast, clear cell apical membranes were labeled along the entire length of the collecting duct. Double labeling of semithin cryostat sections with a specific antibody and lectin-gold complexes was used to demonstrate that the intercalated cells in all regions studied contained carbonic anhydrase, even though the lectin binding differed. These results indicate that, in terms of their glycocalyx composition, intercalated cells represent a heterogeneous population in different regions of the collecting duct.

Localization of ral, a small Mr GTP-binding protein, to collecting duct cells in bovine and rat kidney

1991 ◽  
Vol 261 (6) ◽  
pp. F1063-F1070
Author(s):  
A. Gupta ◽  
B. Bastani ◽  
P. Chardin ◽  
K. A. Hruska
Keyword(s):  
Gene Product ◽  
Plasma Membranes ◽  
Binding Protein ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Kidney Cortex ◽  
Gtp Binding Protein ◽  
Bovine Kidney ◽  
Gtp Binding ◽  
Collecting Ducts

Plasma membranes from bovine kidney cortex were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to nitrocellulose membranes. Blotting with [alpha-32P]GTP and [35S]GTP gamma S demonstrated specific binding to three and six distinct protein bands, respectively, in the 20,000- to 29,000-Mr range. This indicated the presence of small Mr GTP binding proteins (smg) in bovine kidney cortex. Only one smg with 28,000 Mr was labeled with hydrolysis-resistant GTP photoaffinity probe p3-(4-azidoanilido)-p1-5GTP (AAGTP). The major smg in platelet membranes that binds GTP on nitrocellulose blots has been identified as ral-Mr 29,000. With the use of an antiserum against the ral A gene product, one of the smg with Mr of 29,000 present in bovine renal cortical plasma membranes was identified as ral. Ral was absent from glomerular homogenate, suggesting that it is localized to the tubular segments of the nephron. Ral was detected only in the particulate fraction and not the cytosol. Further subcellular localization of ral was investigated by immunohistochemical staining. Anti-ral antibody immunostained the apical and basolateral membranes of cells in the cortical and medullary collecting ducts in a speckled pattern in the bovine kidney. In the rat kidney, however, uniform linear staining of cortical and medullary collecting ducts predominantly localized to the apical membrane was observed. To date, no function has been assigned to ral. Localization of the ral gene product to the collecting duct suggests a specific functional role for this GTP-binding protein.

Biogenesis of Epithelial Cell Plasma Membranes

2008 ◽  
pp. 184-208
Author(s):  
Michael J. Rindler ◽  
Ivan Emanuilov Ivanov ◽  
Enrique J. Rodriguez-Boulan ◽  
David D. Sabatini
Keyword(s):  
Epithelial Cell ◽  
Plasma Membranes ◽  
Cell Plasma

Growth hormone stimulates IGF I gene expression in isolated rat renal collecting duct

1990 ◽  
Vol 259 (3) ◽  
pp. F474-F479 ◽  
Author(s):  
S. A. Rogers ◽  
S. B. Miller ◽  
M. R. Hammerman
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Plasma Membranes ◽  
Collecting Duct ◽  
Dependent Manner ◽  
Collecting Ducts ◽  
Igf I ◽  
Renal Collecting Duct ◽  
I Gene

To determine whether growth hormone (GH) directly stimulates insulin-like growth factor I (IGF I) gene expression in renal collecting duct, plasma membranes prepared from collecting ducts isolated from rat kidney, and collecting ducts themselves were incubated in presence and absence of GH. GH enhanced phospholipase C activity in collecting duct plasma membranes establishing the potential for GH-signal transduction. Inclusion of GH in suspensions of collecting ducts increased production of immunoreactive IGF I in a time-dependent and concentration-dependent manner. Production was stimulated significantly by addition of 10(-10), 10(-8), or 10(-6) M GH to suspensions for 2 h. IGF I produced in isolated collecting ducts was released into the suspending media. Levels of IGF I mRNA in collecting ducts were increased 2.8-fold after incubation with 10(-6) M GH in vitro. IGF I of collecting duct origin was indistinguishable from recombinant human IGF I in terms of its size and receptor-binding characteristics. Our findings demonstrate a direct action of GH to enhance collecting duct IGF I gene expression in vitro. Such enhancement is likely to reflect the mechanism by which GH stimulates renal IGF I production in intact kidney.

scholarly journals Vasopressin Increases Urinary Acidification via V1a Receptors in Collecting Duct Intercalated Cells

2019 ◽  
Vol 30 (6) ◽  
pp. 946-961 ◽  
Author(s):  
Torsten Giesecke ◽  
Nina Himmerkus ◽  
Jens Leipziger ◽  
Markus Bleich ◽  
Taka-aki Koshimizu ◽  
...  
Keyword(s):  
Calcium Release ◽  
Ex Vivo ◽  
Collecting Duct ◽  
Similar Response ◽  
Brattleboro Rats ◽  
Intercalated Cells ◽  
Urinary Ph ◽  
Urinary Acidification ◽  
Collecting Ducts ◽  
And Function

BackgroundAntagonists of the V1a vasopressin receptor (V1aR) are emerging as a strategy for slowing progression of CKD. Physiologically, V1aR signaling has been linked with acid-base homeostasis, but more detailed information is needed about renal V1aR distribution and function.MethodsWe used a new anti-V1aR antibody and high-resolution microscopy to investigate Va1R distribution in rodent and human kidneys. To investigate whether V1aR activation promotes urinary H+ secretion, we used a V1aR agonist or antagonist to evaluate V1aR function in vasopressin-deficient Brattleboro rats, bladder-catheterized mice, isolated collecting ducts, and cultured inner medullary collecting duct (IMCD) cells.ResultsLocalization of V1aR in rodent and human kidneys produced a basolateral signal in type A intercalated cells (A-ICs) and a perinuclear to subapical signal in type B intercalated cells of connecting tubules and collecting ducts. Treating vasopressin-deficient Brattleboro rats with a V1aR agonist decreased urinary pH and tripled net acid excretion; we observed a similar response in C57BL/6J mice. In contrast, V1aR antagonist did not affect urinary pH in normal or acid-loaded mice. In ex vivo settings, basolateral treatment of isolated perfused medullary collecting ducts with the V1aR agonist or vasopressin increased intracellular calcium levels in ICs and decreased luminal pH, suggesting V1aR-dependent calcium release and stimulation of proton-secreting proteins. Basolateral treatment of IMCD cells with the V1aR agonist increased apical abundance of vacuolar H+-ATPase in A-ICs.ConclusionsOur results show that activation of V1aR contributes to urinary acidification via H+ secretion by A-ICs, which may have clinical implications for pharmacologic targeting of V1aR.

Vasopressin induces expression of the Cl−/HCO3− exchanger SLC26A7 in kidney medullary collecting ducts of Brattleboro rats

2006 ◽  
Vol 290 (5) ◽  
pp. F1194-F1201 ◽  
Author(s):  
Snezana Petrovic ◽  
Hassane Amlal ◽  
Xuming Sun ◽  
Fiona Karet ◽  
Sharon Barone ◽  
...  
Keyword(s):  
Western Blot ◽  
Blot Analysis ◽  
Collecting Duct ◽  
Brattleboro Rats ◽  
Intercalated Cells ◽  
Collecting Ducts ◽  
Before And After ◽  
Mild Reduction ◽  
Medullary Collecting Duct

SLC26A7 is a newly identified basolateral Cl−/HCO3− exchanger specific to α-intercalated cells of the outer medullary collecting duct (OMCD). The purpose of the present experiments was to examine the expression of SLC26A7 in kidneys of vasopressin-deficient Brattleboro rats before and after treatment with desamino-Cys1,d-Arg8-vasopressin (dDAVP). Brattleboro rats were treated with dDAVP, a vasopressin analog, for 8 days, and their kidneys were examined for the expression of SLC26A7. The expression of SLC26A7 protein, as examined by immunofluorescence, was undetectable in kidneys of Brattleboro rats. However, treatment with dDAVP induced expression of SLC26A7 protein, restoring it to levels observed in normal rats. These results were verified by Western blot analysis. The mRNA expression of SLC26A7 remained unchanged in response to dDAVP. Immunofluorescent labeling demonstrated abundant levels of anion exchanger type 1 in the OMCD of Brattleboro rats and a mild reduction in response to dDAVP. The abundance of H+-ATPase was not affected by dDAVP. The increased SLC26A7 expression directly correlated with enhanced aquaporin-2 expression, which is proportional to increased interstitial osmolarity in the medulla. In conclusion, vasopressin increases the expression of SLC26A7 protein through posttranscriptional mechanisms in the OMCD. The induction of SLC26A7 by vasopressin in OMCD cells of Brattleboro rats is likely an attempt by cells to regulate their cell volume and maintain HCO3− absorption in a state associated with increased interstitial medullary tonicity.

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