Electrophysiological identification of principal and intercalated cells in the rabbit outer medullary collecting duct

1987 ◽  
Vol 409 (1-2) ◽  
pp. 138-141 ◽  
Author(s):  
Bruce M. Koeppen
Keyword(s):  
Collecting Duct ◽  
Intercalated Cells ◽  
Medullary Collecting Duct ◽  
Principal And Intercalated Cells

Cellular morphology in outer medullary collecting duct: effect of 75% nephrectomy and K+ depletion

1992 ◽  
Vol 263 (6) ◽  
pp. F1119-F1127
Author(s):  
R. K. Zalups ◽  
D. A. Henderson
Keyword(s):  
Renal Mass ◽  
Morphological Changes ◽  
Collecting Duct ◽  
Fractional Excretion ◽  
Potassium Depletion ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Medullary Collecting Duct ◽  
Principal And Intercalated Cells ◽  
K Depletion

The present study was designed to determine, in rats, whether 75% nephrectomy and potassium depletion affect the principal and intercalated cells in the outer medullary collecting duct in the same manner as they affect the principal and intercalated cells in the cortical collecting duct. Ten days after a 75% reduction of renal mass, whole animal glomerular filtration rate decreased and the fractional excretion of potassium increased in rats. However, no morphological changes occurred in either the principal or intercalated cells of the outer medullary collecting duct after the reduction of renal mass. When 75% nephrectomized rats were placed on a diet deficient in potassium, the concentration of potassium in plasma and the absolute and fractional excretion of potassium decreased significantly. In addition, marked hypertrophy occurred in both the principal and intercalated cells in the outer medullary collecting duct. Previous findings from the same animals used in the present study show that 75% nephrectomy caused hypertrophic changes in principal cells of the cortical collecting duct, which could be inhibited by potassium depletion induced by the dietary restriction of potassium. The findings also show that the intercalated cells of the cortical collecting duct in 75% nephrectomized rats were unaffected by potassium depletion. On the basis of our findings, it appears there is an absence of hypertrophy in either the principal or intercalated cells in the outer medullary collecting duct of the rat after renal mass in the animal is reduced significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Characterization of anion exchangers in an inner medullary collecting duct cell line.

1998 ◽  
Vol 9 (5) ◽  
pp. 746-754
Author(s):  
G Obrador ◽  
H Yuan ◽  
T M Shih ◽  
Y H Wang ◽  
M A Shia ◽  
...  
Keyword(s):  
Cell Line ◽  
Anion Exchanger ◽  
Collecting Duct ◽  
Basolateral Membrane ◽  
Disulfonic Acid ◽  
Kidney Cortex ◽  
Intercalated Cells ◽  
Rat Stomach ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

Although the inner medullary collecting duct (IMCD) plays a major role in urinary acidification, the molecular identification of many of the specific components of the transport system in this nephron segment are lacking. A cultured line of rat IMCD cells was used to characterize the mediators of cellular HCO3 exit. This cell line functionally resembles alpha-intercalated cells. Physiologic experiments document that HCO3- transport is a reversible, electroneutral, Cl dependent, Na+-independent process. It can be driven by Cl-gradients and inhibited by stilbenes such as 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid. Immunohistochemical analysis, using a rabbit polyclonal antibody against the carboxy-terminal 12 amino acids of anion exchanger 1 (AE1), revealed a distribution of immunoreactive protein that is consistent with a basolateral localization of AE in cultured cells and in alpha-intercalated cells identified in sections of rat kidney cortex. Immunoblot revealed two immunoreactive bands (approximately 100 and 180 kD in size) in membranes from cultured IMCD cells, rat renal medulla, and freshly isolated IMCD cells. The mobility of the lower molecular weight band was similar to that of AE1 in red blood cell ghosts and kidney homogenate and therefore probably represents AE1. The mobility of the 180-kD band is similar to that for rat stomach and kidney AE2 and therefore probably represents AE2. Selective biotinylation of the apical or basolateral membrane proteins in cultured IMCD cells revealed that both AE1 and AE2 are polarized to the basolateral membrane. Northern blot analysis documented the expression of mRNA for AE1 and AE2 but not AE3. Furthermore, the cDNA sequence of AE1 and AE2 expressed by these cells was found to be virtually identical to that reported for kidney AE1 and rat stomach AE2. It is concluded that this cultured line of rat IMCD cells expresses two members of the anion exchanger gene family, AE1 and AE2, and both of these exchangers probably mediate the electroneutral Cl--dependent HCO3-transport observed in this cell line.

Minealocorticoid receptors and 11 beta-steroid dehydrogenase activity in renal principal and intercalated cells

1994 ◽  
Vol 266 (1) ◽  
pp. F76-F80 ◽  
Author(s):  
A. Naray-Fejes-Toth ◽  
E. Rusvai ◽  
G. Fejes-Toth
Keyword(s):  
Cell Sorting ◽  
Direct Action ◽  
Collecting Duct ◽  
Cell Types ◽  
Target Cells ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Specific Receptors ◽  
Principal And Intercalated Cells ◽  
Steroid Dehydrogenase

Aldosterone exerts complex effects on the cortical collecting duct (CCD): it increases Na+ and K+ transport, and it also influences H+ and HCO3 transport. Whether these latter effects represent direct action of aldosterone on intercalated cells (ICC) or are secondary to changes in the transport of other electrolytes is unclear. Because the presence of specific receptors is the prerequisite of a direct steroid action, and mineralocorticoid receptors (MR) have not yet been demonstrated in ICC, in this study we determined the density of MR directly in isolated principal cells (PC) and beta-ICC. Purified populations of these two cell types were obtained from rabbit renal cortex by immunodissection and fluorescence-activated cell sorting. We found that both PC and beta-ICC contained a significant number of MR, although receptor density was higher in PC than in beta-ICC (6,704 +/- 912 vs. 2,181 +/- 388 MR sites/cell; P < 0.001). 11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD), an enzyme that is present predominantly in mineralocorticoid target cells, exhibited a distribution similar to that of MR in the two cell types. 11 beta-OHSD activity, determined by measuring the rate of conversion of [3H]corticosterone to 11-dehydrocorticosterone, was 1.08 +/- 0.14 and 0.34 +/- 0.08 fmol.min-1 x 1,000 cells-1 (P < 0.001) in intact PC and beta-ICC, respectively. 11 beta-OHSD in both cell types utilized NAD as cofactor. These results suggest that beta-ICC are potential direct targets of aldosterone and that MR in both PC and beta-ICC are protected by 11 beta-OHSD.

Three distinct cell populations in rat kidney collecting duct

1987 ◽  
Vol 253 (2) ◽  
pp. C323-C328 ◽  
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.

scholarly journals Angiotensin II Stimulates Vacuolar H+-ATPase Activity in Renal Acid-Secretory Intercalated Cells from the Outer Medullary Collecting Duct

2007 ◽  
Vol 18 (7) ◽  
pp. 2085-2093 ◽  
Author(s):  
Florina Rothenberger ◽  
Ana Velic ◽  
Paul A. Stehberger ◽  
Jana Kovacikova ◽  
Carsten A. Wagner
Keyword(s):  
Angiotensin Ii ◽  
Atpase Activity ◽  
Collecting Duct ◽  
Intercalated Cells ◽  
Medullary Collecting Duct

Renal expression of the ammonia transporters, Rhbg and Rhcg, in response to chronic metabolic acidosis

2006 ◽  
Vol 290 (2) ◽  
pp. F397-F408 ◽  
Author(s):  
Ramanathan M. Seshadri ◽  
Janet D. Klein ◽  
Shelley Kozlowski ◽  
Jeff M. Sands ◽  
Young-Hee Kim ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Protein Expression ◽  
Mrna Expression ◽  
Collecting Duct ◽  
Broad Band ◽  
Ammonia Excretion ◽  
Intercalated Cells ◽  
Outer Medulla ◽  
Chronic Metabolic Acidosis ◽  
Medullary Collecting Duct

Chronic metabolic acidosis induces dramatic increases in net acid excretion that are predominantly due to increases in urinary ammonia excretion. The current study examines whether this increase is associated with changes in the expression of the renal ammonia transporter family members, Rh B glycoprotein (Rhbg) and Rh C glycoprotein (Rhcg). Chronic metabolic acidosis was induced in Sprague-Dawley rats by HCl ingestion for 1 wk; control animals were pair-fed. After 1 wk, metabolic acidosis had developed, and urinary ammonia excretion increased significantly. Rhcg protein expression was increased in both the outer medulla and the base of the inner medulla. Intercalated cells in the outer medullary collecting duct (OMCD) and in the inner medullary collecting duct (IMCD) in acid-loaded animals protruded into the tubule lumen and had a sharp, discrete band of apical Rhcg immunoreactivity, compared with a flatter cell profile and a broad band of apical immunolabel in control kidneys. In addition, basolateral Rhcg immunoreactivity was observed in both control and acidotic kidneys. Cortical Rhcg protein expression and immunoreactivity were not detectably altered. Rhcg mRNA expression was not significantly altered in the cortex, outer medulla, or inner medulla by chronic metabolic acidosis. Rhbg protein and mRNA expression were unchanged in the cortex, outer and inner medulla, and no changes in Rhbg immunolabel were evident in these regions. We conclude that chronic metabolic acidosis increases Rhcg protein expression in intercalated cells in the OMCD and in the IMCD, where it is likely to mediate an important role in the increased urinary ammonia excretion.

scholarly journals Histochemical carbonic anhydrase in rat inner medullary collecting duct.

1992 ◽  
Vol 40 (10) ◽  
pp. 1535-1545 ◽  
Author(s):  
J G Kleinman ◽  
J L Bain ◽  
C Fritsche ◽  
D A Riley
Keyword(s):  
Carbonic Anhydrase ◽  
Collecting Duct ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Intercalated Cells ◽  
Cell Type ◽  
Variable Intensity ◽  
Inner Medullary Collecting Duct ◽  
Majority Population ◽  
Medullary Collecting Duct

Rat inner medullary collecting duct (IMCD) secretes substantial amounts of H+. However, carbonic anhydrase (CA), a concomitant of H+ secretion, has been generally reported absent in this segment. To reexamine this problem, we investigated CA and the morphological phenotypes of cells comprising the IMCD by CA histochemistry, using a modified Hansson technique with light and electron microscopy. Throughout the medulla, tubule cells exhibit histochemical CA activity. In the initial third of the inner medulla, a small proportion have features of intercalated cells and demonstrate some degree of CA activity. However, the majority population in the early portions of the IMCD appears to consist of principal cells. These also show CA staining of widely variable intensity, both among and within cells. A third cell type, previously called "IMCD cells", appears in the middle portion of the IMCD and is the only cell type present near the papilla tip. In contrast to previous reports, these "IMCD cells" have histochemical CA staining, also of highly variable intensity. These results demonstrate that stainable carbonic anhydrase to support acidification is present throughout the rat IMCD, both in intercalated cells and in some cells clearly not of this type. Therefore, the presence of CA is not specific for the intercalated cell type and suggests that other cell types may participate in acid secretion in IMCD.

Immunolocalization of electroneutral Na-HCO3 − cotransporter in rat kidney

2000 ◽  
Vol 279 (5) ◽  
pp. F901-F909 ◽  
Author(s):  
Henrik Vorum ◽  
Tae-Hwan Kwon ◽  
Christiaan Fulton ◽  
Brian Simonsen ◽  
Inyeong Choi ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Electron Microscopic Level ◽  
Thick Ascending Limb ◽  
Intercalated Cells ◽  
Electron Microscopic ◽  
Outer Medulla ◽  
Outer Stripe ◽  
Medullary Collecting Duct

An electroneutral Na-HCO3 − cotransporter (NBCN1) was recently cloned, and Northern blot analyses indicated its expression in rat kidney. In this study, we determined the cellular and subcellular localization of NBCN1 in the rat kidney at the light and electron microscopic level. A peptide-derived antibody was raised against the COOH-terminal amino acids of NBCN1. The affinity-purified antibody specifically recognized one band, ∼180 kDa, in rat kidney membranes. Peptide- N-glycosidase F deglycosylation reduced the band to ∼140 kDa. Immunoblotting of membrane fractions from different kidney regions demonstrated strong signals in the inner stripe of the outer medulla (ISOM), weaker signals in the outer stripe of the outer medulla and inner medulla, and no labeling in cortex. Immunocytochemistry demonstrated that NBCN1 immunolabeling was exclusively observed in the basolateral domains of thick ascending limb (TAL) cells in the outer medulla (strongest in ISOM) but not in the cortex. In addition, collecting duct intercalated cells in the ISOM and in the inner medulla also exhibited NBCN1 immunolabeling. Immunoelectron microscopy demonstrated that NBCN1 labeling was confined to the basolateral plasma membranes of TAL and collecting duct type A intercalated cells. Immunolabeling controls were negative. By using 2,7-bis-carboxyethyl-5,6-caboxyfluorescein, intracellular pH transients were measured in kidney slices from ISOM and from mid-inner medulla. The results revealed DIDS-sensitive, Na- and HCO3 −-dependent net acid extrusion only in the ISOM but not in mid-inner medulla, which is consistent with the immunolocalization of NBCN1. The localization of NBCN1 in medullary TAL cells and medullary collecting duct intercalated cells suggests that NBCN1 may be important for electroneutral basolateral HCO3 − transport in these cells.

H(+)-K(+)-ATPase activity in rat collecting duct segments

1992 ◽  
Vol 262 (4) ◽  
pp. F692-F695 ◽  
Author(s):  
J. D. Gifford ◽  
L. Rome ◽  
J. H. Galla
Keyword(s):  
Atpase Activity ◽  
Marked Decrease ◽  
Collecting Duct ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Acid Base ◽  
Medullary Collecting Duct ◽  
Gastric Proton Pump

Previous studies have suggested the presence of an H(+)-K(+)-ATPase in rat cortical and medullary intercalated cells with similar properties to the gastric proton pump. The purpose of this study was to determine the functional contribution of an H(+)-K(+)-adenosinetriphosphatase(ATPase) to total CO2 (tCO2) transport along the rat collecting duct. After baseline determination of tCO2 transport in isolated perfused collecting duct segments, Sch 28080 (10 microM) was added to either the perfusate or bath. When Sch 28080 was added to the perfusate, there was no effect in the cortical collecting duct (CCD, 20.8 +/- 6.7 vs. 25.3 + 3.0 pmol.mm-1.min-1), but a marked decrease in tCO2 absorption was effected in both the outer medullary (OMCD, 37.6 + 6.2 vs. 10.7 +/- 4.1 pmol.mm-1.min-1) and initial inner medullary collecting duct (IMCD1, 34.4 +/- 8.1 vs. 16.2 +/- 5.6 pmol.mm-1.min-1). In the CCD from rats with acute alkalosis in vivo, Sch 28080 added to the bath inhibited tCO2 secretion in the CCD (-17.1 +/- 4.4 vs 3.5 + 3.3 pmol.mm-1.min-1). These findings suggest that 1) H(+)-K(+)-ATPase is important in tCO2 absorption in the OMCD and IMCD1 and in tCO2 secretion in the CCD, 2) HCO3(-)-absorbing intercalated cells differ functionally in the cortex and medulla, 3) HCO3- secretion is not the reverse process of HCO3- absorption in the CCD, and 4) H(+)-K(+)-ATPase is important in distal acidification under normal and altered acid-base conditions.

Effects of ischemia-reperfusion injury on renal ammonia metabolism and the collecting duct

2007 ◽  
Vol 293 (4) ◽  
pp. F1342-F1354 ◽  
Author(s):  
Ki-Hwan Han ◽  
Hye-Young Kim ◽  
Byron P. Croker ◽  
Sirirat Reungjui ◽  
Su-Youn Lee ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Proximal Tubule ◽  
Renal Injury ◽  
Collecting Duct ◽  
Ischemia Reperfusion ◽  
Ammonia Excretion ◽  
Intercalated Cells ◽  
Acute Renal Injury ◽  
Intercalated Cell ◽  
Medullary Collecting Duct

Acute renal injury induces metabolic acidosis, but its specific effects on the collecting duct, the primary site for urinary ammonia secretion, the primary component of net acid excretion, are incompletely understood. We induced ischemia-reperfusion (I/R) acute renal injury in Sprague-Dawley rats by clamping the renal pedicles bilaterally for 30 min followed by reperfusion for 6 h. Control rats underwent sham surgery without renal pedicle clamping. I/R injury decreased urinary ammonia excretion significantly but did not persistently alter urine volume, Na+, K+, or bicarbonate excretion. Histological examination demonstrated cellular damage in the outer and inner medullary collecting duct, as well as in the proximal tubule and the thick ascending limb of the loop of Henle. A subset of collecting duct cells were damaged and/or detached from the basement membrane; these cells were present predominantly in the outer medulla and were less frequent in the inner medulla. Immunohistochemistry identified that the damaged/detached cells were A-type intercalated cells, not principal cells. Both TdT-mediated dUTP nick-end labeling (TUNEL) staining and transmission electron microscopic examination demonstrated apoptosis but not necrosis. However, immunoreactivity for caspase-3 was observed in the proximal tubule, but not in collecting duct intercalated cells, suggesting that mechanism(s) of collecting duct intercalated cell apoptosis differ from those operative in the proximal tubule. We conclude that I/R injury decreases renal ammonia excretion and is associated with intercalated cell-specific detachment and apoptosis in the outer and inner medullary collecting duct. These effects likely contribute to the metabolic acidosis frequently observed in acute renal injury.

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