scholarly journals Erratum to: Development and Diseases of the Collecting Duct System

2018 ◽  
pp. E1-E1
Author(s):  
Lihe Chen ◽  
Paul J. Higgins ◽  
Wenzheng Zhang
Keyword(s):  
Collecting Duct ◽  
Duct System

Mechanism of ammonia secretion by cortical collecting ducts of rabbits

1984 ◽  
Vol 247 (5) ◽  
pp. F729-F738 ◽  
Author(s):  
M. A. Knepper ◽  
D. W. Good ◽  
M. B. Burg
Keyword(s):  
Fluid Transport ◽  
Collecting Duct ◽  
Bicarbonate Secretion ◽  
Duct System ◽  
Major Site ◽  
Acid Ph ◽  
Collecting Ducts ◽  
Total Ammonia ◽  
Ammonia Addition ◽  
Tubule Fluid

The collecting duct system is a major site of ammonia addition to the tubule fluid. To study the mechanisms involved, we measured total ammonia and total CO2 transport in isolated, perfused cortical collecting ducts (CCD) from deoxycorticosterone-(DOC) treated rabbits. Perfusate and bath solutions contained 25 meq/liter HCO3 and 4 mM total ammonia. Net fluid transport was not significantly different from zero. Net secretion of total CO2 occurred in all tubules (mean collected concentration, 44.2 mM). Despite bicarbonate secretion, there was net secretion of total ammonia (mean collected concentration, 6.4 mM). There was no detectable ammonia addition to the collected fluid when ammonia was excluded from the perfusate and bath, ruling out a major contribution from synthesis. Ouabain did not significantly affect net transport of total ammonia or total CO2. To test the hypothesis that an acid pH disequilibrium may lower the luminal pH enough to drive ammonia secretion by nonionic diffusion, we perfused CCD from DOC-treated rabbits with carbonic anhydrase (CA) (0.1 mg/ml). Without CA, there was net total ammonia secretion (-2.2 pmol X min-1 X mm-1) and net total CO2 secretion (-16.6 pmol X min-1 X mm-1). Luminal CA converted the net total ammonia secretion to net absorption (1.0 pmol X min-1 X mm-1) while the bicarbonate secretion persisted (-11.2 pmol X min X mm-1). We conclude that total ammonia secretion in these tubules occurs primarily by diffusion of NH3 and is dependent on a luminal acid pH disequilibrium.

Arginine vasopressin modulates expression of neuronal NOS in rat renal medulla

2002 ◽  
Vol 283 (3) ◽  
pp. F559-F568 ◽  
Author(s):  
Pierre-Yves Martin ◽  
Mathieu Bianchi ◽  
Frank Roger ◽  
Laurent Niksic ◽  
Eric Féraille
Keyword(s):  
Arginine Vasopressin ◽  
Collecting Duct ◽  
Duct System ◽  
Water Reabsorption ◽  
Enos Expression ◽  
Outer Medulla ◽  
Expression Levels ◽  
Principal Cells ◽  
Nos Isoforms ◽  
Nnos Expression

Arginine vasopressin (AVP) plays a central role in water balance. In principal cells of the collecting duct system, AVP controls the expression of several genes, including aquaporin-2. Because nitric oxide (NO) participates in the regulation of water reabsorption by the collecting duct system, we analyzed the effect of AVP on the expression of NO synthase (NOS) isoforms in the kidney. Rats were either water restricted or water loaded to modify the circulating AVP levels, and expressions of NOS isoforms were assessed by Western blot analysis. In water-restricted rats, endothelial NOS (eNOS) expression increased in the outer medulla, and neuronal NOS (nNOS) expression rose in both the outer medulla and the papilla. Conversely, water loading induced a decrease in expression of nNOS in the outer medulla and papilla but did not alter eNOS expression. Oral administration of the specific V2-receptor antagonist SR-121463B decreased nNOS expression in the outer medulla and papilla but did not alter eNOS expression levels. Finally, the very low nNOS expression levels observed in AVP-deficient Brattleboro rats was restored by AVP infusion for 1 wk. Thus AVP specifically increases nNOS expression levels in the renal outer medulla and papilla. Because nNOS is specifically expressed in principal cells of the collecting duct system, the stimulation of nNOS expression by AVP may participate in the control of water reabsorption.

Renal carbonic anhydrase

1982 ◽  
Vol 243 (4) ◽  
pp. F311-F324 ◽  
Author(s):  
D. C. Dobyan ◽  
R. E. Bulger
Keyword(s):  
Carbonic Anhydrase ◽  
Collecting Duct ◽  
Mammalian Species ◽  
Carbonic Anhydrase Activity ◽  
The Body ◽  
Carbonic Anhydrases ◽  
Duct System ◽  
Renal Carbonic Anhydrase ◽  
Membrane Bound ◽  
Editorial Review

Carbonic anhydrase is a zinc metalloenzyme widely distributed throughout the tissues of the body. This enzyme exists in a number of isozymic forms in most mammalian species. Significant advances over the past decade have been made in characterizing the nature of renal carbonic anhydrase. In the kidney, this enzyme is thought to play a pivotal role in urinary acidification and bicarbonate reabsorption. Two distinct isozymes of carbonic anhydrase have now been identified in the mammalian kidney. A soluble cytoplasmic form, similar if not identical to human erythrocyte carbonic anhydrase C, accounts for the bulk of the renal carbonic anhydrase activity. In addition, a membrane-bound form constituting only about 2--5% of the renal activity has been found in the brush border and basolateral fractions of kidney homogenates. The histochemical and immunocytochemical localization of these isozymes along the nephron and collecting duct system of various mammalian species suggests that marked heterogeneity exists. The Editorial Review examines the biochemical and morphological approaches that have been used to elucidate the nature of renal carbonic anhydrase and to assess its distribution along the urinary tubule. Possible physiological roles for the renal carbonic anhydrases are considered for the different segments of the nephron and collecting duct system.

scholarly journals TRPV4 is a mechanotransducer of fluid flow in principal cells (PC) and intercalated cells (IC) of the renal collecting duct system

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Jonathan Berrout ◽  
Min Jin ◽  
Mykola Mamenko ◽  
Oleg L Zaika ◽  
Oleh Pochynyuk ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Collecting Duct ◽  
Intercalated Cells ◽  
Duct System ◽  
Principal Cells ◽  
Renal Collecting Duct

Reporter gene recombination in juxtaglomerular granular and collecting duct cells by human renin promoter-Cre recombinase transgene

2006 ◽  
Vol 25 (2) ◽  
pp. 277-285 ◽  
Author(s):  
H. Castrop ◽  
M. Oppermann ◽  
Y. Weiss ◽  
Y. Huang ◽  
D. Mizel ◽  
...  
Keyword(s):  
Kidney Development ◽  
Salt Intake ◽  
Collecting Duct ◽  
Regulatory Elements ◽  
Cre Recombinase ◽  
Mrna Levels ◽  
Duct System ◽  
Adult Mice ◽  
Human Renin ◽  
Afferent Arterioles

To assess the feasibility of using the renin promoter for expressing Cre recombinase in juxtaglomerular (JG) cells only, we generated five independent transgenic mouse lines (designated hRen-Cre) expressing Cre recombinase under control of a 12.2-kb human renin promoter. In the kidneys of adult mice Cre mRNA (RT-PCR) was found in the renal cortex, with Cre protein (immunohistochemistry) being localized in afferent arterioles and to a lower degree in interlobular arteries. Cre mRNA levels were regulated in a renin-typical fashion by changes in oral salt intake, water restriction, or isoproterenol infusion, indicating the presence of key regulatory elements within 12.2 kb of the 5′-flanking region of the human renin gene. hRen-Cre mice were interbred with both the ROSA26-EGFP and ROSA26-lacZ reporter strains to assess renin promoter activity from Cre-mediated excision of a floxed stop cassette and subsequent enhanced green fluorescent protein (EGFP) and β-galactosidase (β-gal) detection. In adult mice, β-gal staining and EGFP were observed in afferent arterioles and interlobular arteries, overlapping with Cre protein expression. In addition, intense β-gal staining was found in cortical and medullary collecting ducts where Cre expression was minimal. In embryonic kidneys, β-gal staining was detected in the developing collecting duct system beginning at embryonic day 12, showing substantial activity of the human renin promoter in the branching ureteric bud. Our data indicate that besides its well-known activity in JG cells and renal vessels the human renin promoter is transiently active in the collecting duct system during kidney development, complicating the use of this approach for JG cell-specific excision of floxed targets.

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