scholarly journals Proximal and Distal Nephron-specific Adaptation to Furosemide

2021 ◽  
Author(s):  
Aram J. Krauson ◽  
Steven Schaffert ◽  
Elisabeth M. Walczak ◽  
Jonathan M. Nizar ◽  
Gwen M. Holdgate ◽  
...  
Keyword(s):  
Cell Number ◽  
Differentially Expressed ◽  
Sodium Reabsorption ◽  
Thick Ascending Limb ◽  
Distal Nephron ◽  
Transcriptional Responses ◽  
Cell Hyperplasia ◽  
Diuretic Resistance ◽  
Nephron Segments ◽  
Renal Tubular

ABSTRACTFurosemide, a widely prescribed diuretic for edema-forming states, inhibits sodium reabsorption in the thick ascending limb of the nephron. Tubular adaptation to diuretics has been observed, but the range of mechanisms along the nephron has not been fully explored. Using morphometry, we show that furosemide induces renal tubular epithelial hyperplasia selectively in distal nephron segments. By comparison, we find progressive cellular hypertrophy in proximal and distal nephron segments. We next utilize single cell RNA sequencing of vehicle- and furosemide-treated mice to define potential mechanisms of diuretic resistance. Consistent with distal tubular cell hyperplasia, we detect a net increase in DCT cell number and Birc5, an anti-apoptotic and pro-growth gene, in a subset of DCT cells, as the most prominently up-regulated gene across the nephron. We also map a gradient of cell-specific transcriptional changes congruent with enhanced distal sodium transport. Furosemide stimulates expression of the mitogen IGF-1. Thus, we developed a mouse model of inducible deletion of renal tubular IGF-1 receptor and show reduced kidney growth and proximal, but not distal, tubular hypertrophy by furosemide. Moreover, genes that promote enhanced bioavailability of IGF-1 including Igfbp1 and Igfbp5 are significantly and differentially expressed in proximal tubular segments and correspond to IGF-1R-dependent hypertrophy. In contrast, downstream PI3-kinase signaling genes including Pdk1, Akt1, Foxo3, FKBP4, Eif2BP4, and Spp1 are significantly and differentially expressed in distal nephron segments and correspond to IGF-1R-independent hypertrophy. These findings highlight novel mechanisms of tubular remodeling and diuretic resistance, provide a repository of transcriptional responses to a common drug, and expand the implications of long-term loop diuretic use for human disease.

Dependency of Microdissected Nephron Segments upon Oxidative Phosphorylation and Exogenous Substrates: A Relationship between Tubular Anatomical Location in the Kidney and Metabolic Activity

1989 ◽  
Vol 77 (3) ◽  
pp. 287-295 ◽  
Author(s):  
Shozo Torikai
Keyword(s):  
Collecting Duct ◽  
Anatomical Location ◽  
Thick Ascending Limb ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Nephron Segments ◽  
Henle's Loop ◽  
Renal Tubular ◽  
Substrate Deprivation ◽  
Exogenous Substrates

1. In order to examine the possibility of heterogeneity in the dependence of renal tubular cells upon oxidative phosphorylation and exogenous substrates, the effects of antimycin A and substrate deprivation on adenosine 5′-triphosphate (ATP) content were examined in isolated rat nephron segments in vitro at 37°C. 2. Antimycin A (5 μmol/l) caused varying decrements in cell ATP level within 5 min in the following order: proximal tubules > cortical thick ascending limb of Henle's loop (cTAL) > cortical collecting duct (cCD) in the cortex, and thin descending limb of Henle's loop (TDL) > medullary thick ascending limb of Henle's loop (mTAL) > outer medullary collecting duct (omCD) in the inner stripe of the outer medulla. In the thick ascending limb and the collecting duct, the segments located in the cortex were more sensitive than those in the medulla. 3. Substrate deprivation for 30 min markedly decreased the cell ATP content in cortical and medullary proximal tubules and also in medullary TDL, whereas it caused only a slight decrease in cTAL and mTAL with no change in cCD and omCD. 4. Media made hypertonic by the addition of 200 mmol/l NaCl under aerobic conditions, increased the requirement for exogenous substrates in TDL and mTAL, but not in omCD. This stimulation was seen to a lesser extent in media made hypertonic by the addition of mannitol instead of NaCl. 5. Taking into consideration a knowledge of rat kidney architecture and intrarenal gradient of oxygen partial pressure, it is likely that the observed dependency upon both oxygen and exogenous substrates in the renal tubular cells reflects adaptation of such cells to their anatomical location, and to the availability of those substances in situ. Furthermore, extracellular sodium concentration and osmolarity stimulate metabolic requirements to a different extent among the nephron segments.

Effect of acute unilateral renal denervation on tubular sodium reabsorption in the dog

1977 ◽  
Vol 232 (1) ◽  
pp. F16-F19
Author(s):  
G. Nomura ◽  
T. Takabatake ◽  
S. Arai ◽  
D. Uno ◽  
M. Shimao ◽  
...  
Keyword(s):  
Renal Denervation ◽  
Renal Plasma Flow ◽  
Free Water ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Water Diuresis ◽  
Free Water Clearance ◽  
Water Excretion ◽  
Tubular Sodium Reabsorption ◽  
Renal Tubular

The effects of acute denervation of the kidney on renal tubular sodium and water excretion were studied in anesthetized, hypophysectomized, and cortisone-treated mongrel dogs during stable water diuresis produced by the infusion of 2.5% dextrose. In all experiments, denervation natriuresis, and diuresis were observed without significant change in glomerular filtration rate (GRF) and renal plasma flow (RPF). Fractional sodium delivery to the distal nephron (CNa + CH2O/100 ml GFR) and fractional free water clearance (CH23/100 ml GFR) was significantly greater in the denervated kidney compared with the innervated kidney (9.6+/-1.2 vs. 6.7+/-0.9% and 8.8+/-1.2 vs. 6.5+/-0.8%, respectively). Distal tubular sodium reabsorption (CH2O/(CNa + CH2O)) was not significantly different. We conclude that renal denervation primarily affects the proximal tubule as manifested by a decrease in the reabsorption of sodium and water. A small effect of denervation on the distal nephron is not completely ruled out.

Cell-specific expression of amiloride-sensitive, Na(+)-conducting ion channels in the kidney

1996 ◽  
Vol 271 (4) ◽  
pp. C1303-C1315 ◽  
Author(s):  
F. Ciampolillo ◽  
D. E. McCoy ◽  
R. B. Green ◽  
K. H. Karlson ◽  
A. Dagenais ◽  
...  
Keyword(s):  
Cell Lines ◽  
Collecting Duct ◽  
Extracellular Fluid ◽  
Cation Channel ◽  
Thick Ascending Limb ◽  
Distal Nephron ◽  
Rt Pcr ◽  
Specific Expression ◽  
Nephron Segments ◽  
Medullary Collecting Duct

Amiloride-sensitive, electrogenic Na+ absorption across the distal nephron plays a vital role in regulating extracellular fluid volume and blood pressure. Recently, two amiloride-sensitive, Na(+)-conducting ion channel cDNAs were cloned. One, an epithelial Na(+)-selective channel (ENaC), is responsible for Na+ absorption throughout the distal nephron. The second, a guanosine 3',5'-cyclic monophosphate (cGMP)-inhibitable cation channel, is conductive to Na+ and Ca2+ and contributes to Na+ absorption across the inner medullary collecting duct (IMCD). As a first step toward understanding the segment-specific contributions(s) of cGMP-gated cation channels and ENaC to Na+ and Ca2+ uptake along the nephron, we used in situ reverse transcription-polymerase chain reaction (RT-PCR) hybridization, solution-phase RT-PCR, and Western blot analysis to examine the nephron and cell-specific expression of these channels in mouse kidney cell lines and/or dissected nephron segments. cGMP-gated cation channel mRNA was detected in proximal tubule, medullary thick ascending limb (mTAL), distal convoluted tubule (DCT), cortical collecting duct (CCD), outer medullary collecting duct (OMCD), and IMCD. cGMP-gated cation channel protein was detected in DCT, CCD, and IMCD cell lines. These observations suggest that hormones that modulate intracellular cGMP levels may regulate Na+, and perhaps Ca2+, uptake throughout the nephron. mRNA for alpha-mENaC, a subunit of the mouse ENaC, was detected in mTAL, DCT, CCD, OMCD, and IMCD. Coexpression of alpha-mENaC and cGMP-gated cation channel mRNAs in mTAL, DCT, CCD, OMCD, and IMCD suggests that both channels may contribute to Na+ absorption in these nephron segments.

Identification and localization of BK-β subunits in the distal nephron of the mouse kidney

2007 ◽  
Vol 293 (1) ◽  
pp. F350-F359 ◽  
Author(s):  
P. Richard Grimm ◽  
Ruth M. Foutz ◽  
Robert Brenner ◽  
Steven C. Sansom
Keyword(s):  
Immunohistochemical Staining ◽  
Bk Channels ◽  
Mouse Kidney ◽  
Thick Ascending Limb ◽  
Distal Nephron ◽  
Rt Pcr ◽  
Western Blots ◽  
Nephron Segments ◽  
High K ◽  
Specific Localization

Large-conductance, Ca2+-activated K+ channels (BK), comprised of pore-forming α- and accessory β-subunits, secrete K+ in the distal nephron under high-flow and high-K+ diet conditions. BK channels are detected by electrophysiology in many nephron segments; however, the accessory β-subunit associated with these channels has not been determined. We performed RT-PCR, Western blotting, and immunohistochemical staining to determine whether BK-β1 is localized to the connecting tubule's principal-like cells (CNT) or intercalated cells (ICs), and whether BK-β2-4 are present in other distal nephron segments. RT-PCR and Western blots revealed that the mouse kidney expresses BK-β1, BK-β2, and BK-β4. Available antibodies in conjunction with BK-β1−/− and BK-β4−/− mice allowed the specific localization of BK-β1 and BK-β4 in distal nephron segments. Immunohistochemical staining showed that BK-β1 is localized in the CNT but not ICs of the connecting tubule. The localization of BK-β4 was discerned using an anti-BK-β4 antibody on wild-type tissue and anti-GFP on GFP-replaced BK-β4 mouse (BK-β4−/−) tissue. Both antibodies (anti-BK-β4 and anti-GFP) localized BK-β4 to the thick ascending limb (TAL), distal convoluted tubule (DCT), and ICs of the distal nephron. It is concluded that BK-β1 is narrowly confined to the apical membrane of CNTs in the mouse, whereas BK-β4 is expressed in the TAL, DCT, and ICs.

Defined human renal tubular epithelia in culture: growth, characterization, and hormonal response

1985 ◽  
Vol 248 (3) ◽  
pp. F436-F443 ◽  
Author(s):  
P. D. Wilson ◽  
M. A. Dillingham ◽  
R. Breckon ◽  
R. J. Anderson
Keyword(s):  
Primary Cultures ◽  
Thick Ascending Limb ◽  
Marker Enzyme ◽  
Nephron Segments ◽  
Growth Characterization ◽  
Proximal Straight Tubule ◽  
Collecting Tubule ◽  
Culture Growth ◽  
Renal Tubular

Individually microdissected nephron segments of defined epithelial origin from human kidneys were cultured in vitro in the present studies. Nephron segments of proximal convoluted tubule, proximal straight tubule, cortical thick ascending limb of Henle, and cortical collecting tubule were grown in defined media. Each cell type retained differentiated characteristics as assessed by ultrastructural morphology, marker enzyme profiles, and adenylate cyclase response to selected hormones. These studies demonstrate the feasibility of using primary cultures of well-defined segments of the human nephron to study human renal tubular epithelia in vitro.

Abstract P264: Interaction of Collecting Duct-Derived Prorenin and Soluble Prorenin Receptor Increases Intraluminal Renin Activity and Augments Intratubular Angiotensin II Formation in Ang II-Dependent Hypertensive Rats

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Minolfa C Prieto ◽  
Liu Liu ◽  
Alexis A Gonzalez ◽  
Dale M Seth ◽  
L Gabriel Navar
Keyword(s):  
Angiotensin Ii ◽  
De Novo ◽  
Collecting Duct ◽  
Renin Activity ◽  
Soluble Form ◽  
Sodium Reabsorption ◽  
Ang Ii ◽  
Distal Nephron ◽  
Nephron Segments ◽  
Prorenin Receptor

Upregulation of collecting duct (CD)-derived renin (CD renin) in angiotensin II (Ang II)-dependent hypertension may provide a pathway for intratubular Ang II formation by acting on angiotensinogen (AGT) delivered from proximal tubule segments. Recently, a prorenin/renin receptor (PRR) has been cloned and shown to enhance renin and prorenin activation. The soluble form of the PRR (sPRR) is augmented in the renal inner medulla of chronic Ang II-infused rats. The present study was performed to determine if renin is secreted into the lumen by the CD cells in chronic Ang II-infused rats and to establish the functional contribution of sPRR to the enhanced renin activity in distal nephron segments. Accordingly, urinary levels of renin ( uRen ) and Ang II ( uAngII ) were measured by RIA in chronic Ang II-infused male Sprague-Dawley rats [80 ng/min, SC minipumps for 14 d, n=10] and sham-operated rats [n=10]. Systolic blood pressure increased in the Ang II rats by Day 5 and continued to increase throughout the study (Day 13; Ang II: 175±10 vs. sham: 116±2 mmHg; p <0.05). Although plasma renin activity (PRA) was suppressed in the Ang II-infused rats, renal medullary renin content was significantly augmented (12,605±1,343 vs. 7,956±765 ng Ang I/h/mg; p <0.05). The excretion of uAngII was also increased (3,813±431 vs. 2,080±361 fmol/day; p <0.05). In addition, renin and prorenin excretion rates increased progressively and were markedly augmented by Day 13 of Ang II infusion [renin (8.6±1.5 vs. 2.8±0.5x10 -6 Enzyme Units Excreted (EUE) /day; prorenin: 15.8 ± 2.8 vs. 2.6 ± 0.7x10 -3 EUE /day, p <0.05). Renin and prorenin protein levels examined by Western Blot in the urine were similarly increased. Importantly, the incubation of urine samples of Ang II-infused rats with recombinant human prorenin showed increased Ang I formation compared to sham-operated rats. In conclusion, in chronic Ang II-infused rats, the presence of sPRR in the urine reflects augmented enzymatic activity of prorenin secreted by the principal cells of the CD, which increase intratubular Ang II de novo formation in the distal nephron segments thus contributing to enhanced sodium reabsorption during Ang II-dependent hypertension.

Effects of growth hormone on renal tubular handling of sodium in healthy humans

2001 ◽  
Vol 281 (6) ◽  
pp. E1326-E1332 ◽  
Author(s):  
Troels Krarup Hansen ◽  
Jens Møller ◽  
Klaus Thomsen ◽  
Erik Frandsen ◽  
Rolf Dall ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Day Treatment ◽  
Extracellular Volume ◽  
Plasma Renin ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Water Reabsorption ◽  
Synthesis Inhibition ◽  
Healthy Humans ◽  
Renal Tubular

To investigate the mechanisms behind the water- and sodium-retaining effects of growth hormone (GH), we studied the effect of GH on 1) water and sodium homeostasis, 2) the renin-angiotensin-aldosterone system (RAAS), and 3) lithium clearance (CLi) with and without concomitant prostaglandin (PG) synthesis inhibition with ibuprofen. GH administration for 6 days induced a significant increase in plasma renin, which was abolished by coadministration of ibuprofen (mU · l−1 · 24 h−1: control: 22.4 ± 4.3; GH: 37.7 ± 8.8; ibuprofen: 15.2 ± 3.0; GH + ibuprofen: 19.7 ± 2.5; ANOVA: P < 0.01). Comparable increments in extracellular volume were seen after 6-day treatment with GH alone and in combination with ibuprofen [liters: control, 19.57 ± 0.92; GH, 20.80 ± 1.00 (ANOVA: P< 0.0005); ibuprofen, 19.38 ± 0.90; GH + ibuprofen, 21.63 ± 1.37 (ANOVA: P < 0.0005)]. Treatment with GH increased CLi and changed the tubular handling of sodium and water. The absolute distal sodium reabsorption was increased, and this was only partially counterbalanced by decreased reabsorption in the proximal tubules. The data demonstrate that GH-induced activation of the RAAS can be blocked by concomitant PG synthesis inhibition and that the tubular effects of GH include increased distal nephron sodium and water reabsorption.

Mechanism of PGE2-induced cell swelling in distal nephron segments

1992 ◽  
Vol 263 (5) ◽  
pp. F824-F832
Author(s):  
T. Shimizu ◽  
M. Naruse ◽  
M. Takeda ◽  
M. Nakamura ◽  
K. Yoshitomi ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Cell Swelling ◽  
Rabbit Kidney ◽  
Thick Ascending Limb ◽  
Cortical Collecting Duct ◽  
Distal Nephron ◽  
Nephron Segments ◽  
Pg E2 ◽  
Dose Dependent ◽  
Sustained Increase

The effects of prostaglandin (PG) E2 on cell swelling were studied in isolated perfused tubules of rabbit kidney. PGE2 (1 microM) added to the bath induced cell swelling by 13.4, 7.2, and 9.6% in the connecting tubule, distal convoluted tubule, and cortical collecting duct, respectively, but it had no effect on the proximal convoluted tubule and cortical thick ascending limb. The response was dose dependent in the range of 1 nM to 1 microM. PGI2 exerted a similar effect, but PGF2 alpha had no effect. The swelling was completely blocked by basolateral Na+ removal and was attenuated by bilateral Cl- removal, suggesting that the swelling was mediated by basolateral Na+ entry in association with Cl- entry. In all segments except proximal tubule, PGE2 caused an initial transient peak followed by a sustained increase in intracellular Ca2+. Intracellular Ca2+ chelation or inhibition of Ca2+ release from intracellular stores abolished the PGE2-induced cell swelling, but extracellular Ca2+ removal did not. An inhibitor of the Na(+)-Ca2+ exchanger (3',4'-dichlorobenzamil, 100 microM) in the bath completely inhibited PGE2-induced cell swelling. Neither furosemide (1 mM) nor amiloride (1 mM) added to bath abolished the response, indicating that neither Na(+)-K(+)-2Cl- cotransport nor Na(+)-H+ exchange is involved in the action of PGE2. The swelling response to PGE2 was observed even in the presence of ouabain, indicating that the effect of PGE2 is independent of Na(+)-K(+)-adenosinetriphosphatase inhibition. Nicardipine added to bath partially inhibited the swelling response.(ABSTRACT TRUNCATED AT 250 WORDS)

Substrate utilization by the distal nephron in dogs with chronic metabolic acidosis: studies with ethacrynic acid

1985 ◽  
Vol 63 (12) ◽  
pp. 1565-1569 ◽  
Author(s):  
Mitchell L. Halperin ◽  
Ching B. Chen
Keyword(s):  
Metabolic Acidosis ◽  
Ethacrynic Acid ◽  
Proximal Convoluted Tubule ◽  
Sodium Reabsorption ◽  
Thick Ascending Limb ◽  
Distal Nephron ◽  
Chronic Metabolic Acidosis ◽  
Fractional Excretion Of Sodium ◽  
Renal Oxygen Consumption ◽  
Dog Kidney

Glutamine and lactate oxidations provide the bulk of ATP required for sodium reabsorption in the dog kidney during chronic metabolic acidosis. Indirect evidence has suggested that glutamine is oxidized in the proximal convoluted tubule; if this is true, lactate should be the major fuel of the more distal nephron sites. The purpose of these experiments was to determine which substrates were metabolized by the acidotic dog kidney when a significant proportion of sodium chloride reabsorption was inhibited in the thick ascending limb of the loop of Henle. Ethacrynic acid, a loop diuretic, caused the fractional excretion of sodium to increase from 1 to 34%. The glomerular filtration rate declined somewhat, but there was no significant change in the renal blood flow rate. Renal oxygen consumption declined in conjunction with the natriuresis. However, when the data were examined at a constant filtered load of sodium (a constant rate of ATP turnover), there was no reduction in glutamine uptake or glutamine conversion to ATP in the presence of this natriuretic agent. The major change observed concerned lactate metabolism, in the presence of ethacrynic acid, there was no longer a significant rate of lactate extraction. These data are best explained by assuming that glutamine is the fuel of the proximal convoluted tubule of the acidotic dog kidney, whereas lactate oxidation occurs principally in the nephron sites where sodium reabsorption was inhibited by ethacrynic acid.

Chloride concentration gradient in newborn dogs in the presence of distal nephron blockade

1980 ◽  
Vol 239 (4) ◽  
pp. F328-F335
Author(s):  
Aviad Haramati ◽  
Leonard I. Kleinman
Keyword(s):  
Proximal Tubule ◽  
Ethacrynic Acid ◽  
Chloride Concentration ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Electrolyte Excretion ◽  
Newborn Animal ◽  
Plasma Chloride ◽  
Renal Tubular ◽  
Inner Cortex

Renal tubular Na+, Cl-, and H2O reabsorption was determined in 14 newborn dogs, 3–29 days of age, and in three adult dogs. In all animals NaCl reabsorption beyond the proximal tubule was blocked with ethacrynic acid (2 mg/kg) and amiloride (2.4 mg/kg). During distal blockade, fractional reabsorption of NaCl and water in both newborns and adults was approximately 70%, and there was a urine-to-plasma chloride gradient equal to 1.34 ± 0.01, indicating that the proximal tubules of the newborn as well as those of the adult can generate a transtubular Cl- gradient. Upon administration of acetazolamide (50 mg/kg), there was a dramatic increase in excretion of Na+, Cl-, HCO3-, and water, and a decrease in the transtubular chloride gradient. After acetazolamide, the degree of inhibition of HCO3- reabsorption was well correlated with that of Na+ (r = 0.77) or Cl- (r = 0.74), and Na+ or Cl- inhibition exceeded that of HCO3- In the newborn animal, the ratio of inner-to-outer cortical nephron function is high at birth and declines rapidly during the first few weeks of life. However, there was no correlation between age and changes in either electrolyte excretion or in the transtubular chloride gradient. Therefore, the newborn dog possesses Cl- permselective tubules in the inner cortex that, in the presence of intact HCO3- reabsorption, are capable of establishing a functional transtubular Cl- gradient contributing to NaCl reabsorption. bicarbonate reabsorption; sodium reabsorption; ethacrynic acid; amiloride; acetazolamide; proximal tubule Submitted on October 29, 1979 Accepted on April 18, 1980

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