Probing for the bradykinin B2 receptor in rat kidney by anti-peptide and                anti-ligand antibodies.

The kallikrein-kinin system is involved in the inflammatory process, in blood pressure regulation, and in renal homeostasis. The presence of kallikreins, kininogens, and kinins in renal tissues and fluids is well established; however, the occurrence and distribution of the bradykinin (B2) receptor in the kidney are unknown. Using chemically cross-linked conjugates of bovine serum albumin and the B2 agonist bradykinin or the potent B2 antagonist HOE140, followed by antibodies to the respective ligand and the peroxidase-anti-peroxidase system, we were able to detect the B2 receptor. The receptor has been found in straight portions of the proximal tubules, in distal straight tubules, in connecting tubules, and in collecting ducts of rat kidney. The staining patterns produced by the ligand conjugate-antiligand approach are in agreement with those obtained by conventional autoradiography using [125I]-Tyr0-bradykinin. Immunocytochemical localization of B2 receptor by antipeptide antibodies to the receptor confirmed these findings and demonstrated the presence of B2 receptor in the basal infoldings and luminal membranes of the tubule cells, and in smooth muscle cells of the cortical radial artery and of afferent arterioles. Co-localization of the B2 receptor with kallikrein and kininogens in connecting tubule cell and collecting duct cell layers, respectively, provides a structural basis for the hypothesized physiological functions of the kallikrein-kinin system in the kidney.

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Distribution of immunoreactive kallikrein along the rat nephron

AJP Renal Physiology ◽

10.1152/ajprenal.1983.244.5.f510 ◽

1983 ◽

Vol 244 (5) ◽

pp. F510-F515 ◽

Cited By ~ 4

Author(s):

D. Proud ◽

M. A. Knepper ◽

J. J. Pisano

Keyword(s):

Rat Kidney ◽

Outer Cortex ◽

Kinin System ◽

Nephron Segments ◽

Collecting Ducts ◽

Site Of Action ◽

Collecting Tubules ◽

A Site ◽

Kallikrein Kinin System ◽

Convoluted Tubules

We have used a direct radioimmunoassay to localize kallikrein along the corticomedullary axis of the rat kidney and in microdissected rat cortical nephron segments. As previously seen in rat and dog, kallikrein content was highest in the outer cortex and decreased progressively toward the papillary tip. In microdissected cortical nephron segments, the highest kallikrein content was found in the connecting tubule [176 +/- 16 (SE) pg/mm tubule length (n = 12)]. In addition, a significant amount of kallikrein was found in distal convoluted tubules [53 +/- 4 pg/mm (n = 14)], initial collecting tubules [75 +/- 10 pg/mm (n = 14)], and cortical collecting ducts [37 +/- 4 pg/mm (n = 13)]. Little or no kallikrein was found in glomeruli, proximal convoluted tubules, proximal straight tubules, and cortical thick ascending limbs. These results are compatible with a site of action of the kallikrein-kinin system in the cortical segments of the rat distal nephron.

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K depletion modifies the properties of Sch-28080-sensitive K-ATPase in rat collecting duct

AJP Renal Physiology ◽

10.1152/ajprenal.1997.272.1.f124 ◽

1997 ◽

Vol 272 (1) ◽

pp. F124-F131 ◽

Cited By ~ 13

Author(s):

B. Buffin-Meyer ◽

M. Younes-Ibrahim ◽

C. Barlet-Bas ◽

L. Cheval ◽

S. Marsy ◽

...

Keyword(s):

Collecting Duct ◽

Rat Kidney ◽

Lower Sensitivity ◽

Kinetic Properties ◽

Type I ◽

Type Ii ◽

Distribution Profile ◽

Adenosine Triphosphatases ◽

Collecting Ducts ◽

K Depletion

Two distinct Sch-28080-sensitive K-adenosine triphosphatases (K-ATPases) were previously described in the rat nephron: a ouabain-resistant K-ATPase (type I) present in collecting ducts (CD) and a ouabain-sensitive from (type II) located in proximal tubules (PT) and thick ascending limbs (TAL). In K-depleted rats, K-ATPase activity is increased in CD, whereas it is reduced in PT and TAL. Because expression of colonic H-K-ATPase is restricted to the CD of K-depleted rats, we hypothesized that K-ATPase from the CD of K-depleted rats might be different from types I and II. Indeed, type III K-ATPase displays higher sensitivities to ouabain and to Sch-28080 than type II, a lower sensitivity to Sch-28080 than type I, and, conversely to types I and II, it can be stimulated by Na+. Pharmacological differences between types II and III K-ATPases were confirmed by [3H]ouabain binding experiments. Thus the rat kidney expresses three K-ATPases that differ by their pharmacological and kinetic properties, their distribution profile along the nephron and their behavior during K depletion.

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Developmental expression of the epithelial Na+ channel in kidney and uroepithelia

AJP Renal Physiology ◽

10.1152/ajprenal.1999.276.2.f304 ◽

1999 ◽

Vol 276 (2) ◽

pp. F304-F314 ◽

Cited By ~ 12

Author(s):

Shigeru Watanabe ◽

Kazumichi Matsushita ◽

Paul B. McCray ◽

John B. Stokes

Keyword(s):

Urinary Bladder ◽

Collecting Duct ◽

Rat Kidney ◽

Rnase Protection Assay ◽

Adult Life ◽

Developmental Expression ◽

Na Channel ◽

Rnase Protection ◽

Collecting Ducts ◽

Uroepithelial Cell

The epithelial Na+ channel (ENaC) plays an important role in regulating Na+ balance in neonatal and adult life. Using in situ hybridization, we localized α-, β-, and γ-rat ENaC (rENaC) mRNA in developing rat kidney and uroepithelia. rENaC mRNA was first detectable on fetal day 16, and by fetal day 17, mRNA was abundant in the terminal collecting duct and uroepithelia. After birth, the intensity of the signals for all three subunits increased in the cortical collecting ducts and by 9 days after birth had diminished in the inner medullary collecting ducts. Expression in uroepithelial cells was different. mRNA for β- and γ-rENaC, but not α-rENaC, was detected in pelvis, ureters, and bladder at all stages of development beyond fetal day 16. By RNase protection assay (RPA), the greatest increase in subunit abundance in the kidney occurred before birth. Between postnatal days 9 and 30, the abundance of β- and γ-rENaC decreased relative to α-rENaC in outer and inner medulla. The urinary bladder, in contrast, demonstrated the greatest increase in β- and γ-rENaC mRNA abundance after birth. We were generally unable to detect α-rENaC by RPA in urinary bladder. Feeding weaned rats a diet of high or low NaCl did not change the abundance of any of the subunit mRNAs in bladder. These results demonstrate additional heterogeneity of developmental expression and regulation of ENaC. The differences between the collecting duct and uroepithelial cell rENaC mRNA regulation raise the possibility of significant differences in function.

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Three distinct cell populations in rat kidney collecting duct

AJP Cell Physiology ◽

10.1152/ajpcell.1987.253.2.c323 ◽

1987 ◽

Vol 253 (2) ◽

pp. C323-C328 ◽

Cited By ~ 38

Author(s):

H. Holthofer ◽

B. A. Schulte ◽

G. Pasternack ◽

G. J. Siegel ◽

S. S. Spicer

Keyword(s):

Collecting Duct ◽

Rat Kidney ◽

Morphological Characteristics ◽

Anion Channel ◽

Band 3 ◽

Cell Populations ◽

Intercalated Cells ◽

Distinct Cell ◽

Collecting Ducts ◽

Principal And Intercalated Cells

The morphologically heterogeneous cell populations in the collecting ducts of the rat kidney were studied using immunocytochemical detection of Na+-K+-ATPase and the anion channel (band 3) glycoprotein. Both enzymes were localized to the basal aspect of separate and morphologically distinct subpopulations of cells in various segments of the collecting duct. Na+-K+-ATPase appeared to be present exclusively in principal cells as identified by their morphology, whereas band 3 antibodies reacted only with intercalated cells. However, 5-20% of cells with the morphological characteristics of intercalated cells failed to react with either antisera in various segments of collecting ducts. As band 3 glycoprotein serves in exchanging intracellular bicarbonate for chloride, it is highly likely that the cells positive for this antigen secrete protons. The method introduced here appears thus useful for distinguishing between principal and intercalated cells by differences in their enzyme content and further for revealing two subpopulations of intercalated cells. This method promises to provide a useful approach for studying the principal and intercalated cell populations in various metabolic states.

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

AJP Cell Physiology ◽

10.1152/ajpcell.1985.248.3.c348 ◽

1985 ◽

Vol 248 (3) ◽

pp. C348-C356 ◽

Cited By ~ 41

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.

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Focal expression of insulin-like growth factor I in rat kidney collecting duct.

The Journal of Cell Biology ◽

10.1083/jcb.107.2.811 ◽

1988 ◽

Vol 107 (2) ◽

pp. 811-819 ◽

Cited By ~ 71

Author(s):

J D Bortz ◽

P Rotwein ◽

D DeVol ◽

P J Bechtel ◽

V A Hansen ◽

...

Keyword(s):

Growth Factor ◽

Collecting Duct ◽

Rat Kidney ◽

Insulin Like Growth Factor ◽

Highly Sensitive ◽

Collecting Ducts ◽

Igf I ◽

Hypophysectomized Rats ◽

Experimental Approaches ◽

Focal Expression

To address the question of insulin-like growth factor (IGF) I localization and synthesis in kidney, we used two complementary experimental approaches: immunohistochemistry of fixed paraffin-embedded rat kidney sections; and measurement of IGF I mRNA in isolated components of the rat nephron, using a highly sensitive and specific solution hybridization assay. Immunostainable IGF I was localized exclusively to principal cells of cortical and medullary collecting ducts. Administration of growth hormone to hypophysectomized rats for 8 d resulted in enhanced immunohistochemical staining of IGF I within collecting ducts, but no detectable IGF I in other portions of the nephron. The abundance of IGF I mRNA was 7-12-fold higher in isolated papillary collecting ducts than in proximal tubules or glomeruli, and was enriched 10-fold compared with whole kidney. Our data demonstrate colocalization of IGF I and IGF I mRNA in the collecting duct, consistent with focal expression of the IGF I gene at this site.

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Lack of effect of atrial natriuretic peptide and urodilatin on vasopressin-stimulated cyclic AMP production in microdissected rat inner medullary collecting ducts

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0120149 ◽

1994 ◽

Vol 12 (2) ◽

pp. 149-154

Author(s):

W J Burgess ◽

M N Perrott ◽

R J Balment

Keyword(s):

Cyclic Amp ◽

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Collecting Duct ◽

Rat Kidney ◽

Absolute Magnitude ◽

Camp Production ◽

Collecting Ducts ◽

Medullary Collecting Duct ◽

Atrial Natriuretic

ABSTRACT It is unclear whether the diuretic effects of atrial natriuretic peptide (ANP) result, in part, from an inhibition of the renal actions of vasopressin. Moreover, accruing evidence suggests that the kidneys themselves may produce an ANP-like peptide, urodilatin, which shares many of the renal actions of ANP. The mechanism underlying the diuretic action of urodilatin has not yet been examined. Accordingly, we have investigated the potential modulatory actions of both ANP and urodilatin on vasopressin-stimulated cyclic AMP (cAMP) production in microdissected inner medullary collecting duct (IMCD) segments of rat kidney. ANP and urodilatin alone (at 10−8 or 10−6 m) had no demonstrable effect on cAMP accumulation in IMCD segments. Moreover, neither ANP nor urodilatin (each at 10−6 m) significantly altered either the profile or the absolute magnitude of the cAMP response stimulated by vasopressin. These findings indicate that neither ANP nor urodilatin interacts with the vasopressin-sensitive adenylate cyclase site in the rat IMCD to contribute to its diuretic actions.

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NBCn1 is a basolateral \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{Na}^{+}\mathrm{-HCO}_{3}^{-}\) \end{document} cotransporter in rat kidney inner medullary collecting ducts

AJP Renal Physiology ◽

10.1152/ajprenal.00437.2002 ◽

2004 ◽

Vol 286 (5) ◽

pp. F903-F912 ◽

Cited By ~ 44

Author(s):

Jeppe Praetorius ◽

Young-Hee Kim ◽

Elena V. Bouzinova ◽

Sebastian Frische ◽

Aleksandra Rojek ◽

...

Keyword(s):

Collecting Duct ◽

Rat Kidney ◽

Basolateral Membrane ◽

Primary Cultures ◽

Thick Ascending Limb ◽

Medullary Thick Ascending Limb ◽

Collecting Ducts ◽

Basolateral Plasma Membrane ◽

Medullary Collecting Duct ◽

Plasma Membrane Domain

Primary cultures of rat inner medullary collecting duct (IMCD) cells Na+ dependently import [Formula: see text] across the basolateral membrane through an undefined transport protein. We used RT-PCR, immunoblotting, and immunohistochemistry to identify candidate proteins for this basolateral [Formula: see text] cotransport. The mRNA encoding the electroneutral [Formula: see text] cotransporter NBCn1 was detected as the only [Formula: see text] cotransporter in the rat inner medulla (IM) among the five characterized Na+-dependent [Formula: see text] transporters. The mRNA of a yet uncharacterized transporter-like protein, BTR1, was also present in the IM, but its expression in microdissected tubules seemed restricted to the thin limbs of Henle's loop. Immunoblotting confirmed the presence of NBCn1 as an ∼180-kDa protein of the rat IM. Anti-NBCn1 immunolabeling was confined to the basolateral plasma membrane domain of IMCD cells in the papillary two-thirds of the IM. Consistent with the presence of NBCn1, IMCD cells possessed stilbene-insensitive, Na+- and [Formula: see text]-dependent pH recovery after acidification, as assessed by fluorescence microscopy using a pH-sensitive intracellular dye. In furosemide-induced alkalotic rats, NBCn1 protein abundance was decreased in both the IM and inner stripe of outer medulla (ISOM) as determined by immunoblotting and immunohistochemistry. In contrast, NBCn1 abundance in the IM and ISOM was unchanged in NaHCO3-loaded animals, and the NBCn1 abundance increased only in the ISOM after NH4Cl loading. In conclusion, NBCn1 is a basolateral [Formula: see text] cotransporter of IMCD cells and is differentially regulated in IMCD and medullary thick ascending limb.

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

AJP Renal Physiology ◽

10.1152/ajprenal.1991.261.6.f1063 ◽

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.

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Effects of hypertonicity on ADH-stimulated water permeability in rat inner medullary collecting duct

AJP Renal Physiology ◽

10.1152/ajprenal.1990.258.2.f266 ◽

1990 ◽

Vol 258 (2) ◽

pp. F266-F272 ◽

Cited By ~ 5

Author(s):

S. P. Nadler

Keyword(s):

Antidiuretic Hormone ◽

Water Permeability ◽

Collecting Duct ◽

Rat Kidney ◽

Water Reabsorption ◽

Cyclic Monophosphate ◽

Collecting Ducts ◽

Significant Augmentation ◽

Medullary Collecting Duct ◽

A Site

To assess the effects of increased tonicity on water reabsorption (Jv) in inner medullary collecting ducts (IMCD), antidiuretic hormone (ADH)-stimulated Jv and water permeability (PF) were determined in microperfused IMCD dissected from the inner medulla of rat kidney. In IMCD exposed to a 150-mosmol/kgH2O gradient in isotonic bath, ADH-stimulated PF averaged 719 +/- 93 microns/s. Symmetric addition of 75 mM NaCl to perfusate and bath resulted in a significant augmentation of ADH-stimulated PF (56%) that was reversible when initial solutions were restored. Despite the increase in PF, JV did not change but would have decreased by 16% (P less than 0.01) had PF not increased, because of the greater absolute axial increase in luminal tonicity that occurs with more hypertonic luminal solutions. When 150 mM mannitol was used to increase tonicity, similar effects were observed. However, 150 mM urea had no effect on ADH-stimulated PF. In IMCD exposed to 8-para-(chlorophenylthio)-adenosine 3',5'-cyclic monophosphate, addition of 75 mM NaCl to both and perfusate also resulted in a 76% increase in PF. These results are the first to demonstrate directly that increased effective tonicity augments ADH-stimulated PF in rat IMCD at a site distal to adenosine 3',5'-cyclic monophosphate generation. This effect may contribute to maintenance of medullary interstitial tonicity during antidiuresis by ensuring that most water reabsorption occurs more proximally within the IMCD.

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