Biochemical and Physiological Studies on Cells Isolated From the Medullary Thick Ascending Limb of Henle's Loop

Eveloff, Jill; Bayerdörffer, Eckehard; Haase, Winfried; Kinne, Rolf

doi:10.1016/b978-0-08-025517-0.50018-7

Cited by 4 publications

(5 citation statements)

References 11 publications

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“…Ouabain also depressed the 02 consumption to a greater extent. Interestingly, these inhibitions of transport decreased the 02 consumption by about 50% of the control value, which were about the same as that observed in isolated cells from the outer medulla of the mammalian kidney (EVELOFF et al, 1980(EVELOFF et al, , 1981. The control value of the early distal tubule in this study was smaller than that of the OXYGEN CONSUMPTION ON THE EARLY DISTAL TUBULE isolated cell which was prepared from the thick ascending limb of Henle's loop of a rabbit (526.7 nl • min-1 • mg-1 protein) (EVELOFF et al, 1981).…”

Section: Discussionsupporting

confidence: 68%

Dependence of oxygen consumption on Cl- transport and metabolic substrates in the early distal tubule of the Triturus kidney.

Kuramochi

1986

Jpn.J.Physiol

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The early distal tubule (eDT) and the proximal tubule (PT) were dissected as tissue samples from the Triturus kidney. The oxygen consumption (Qo2) of these tubules was measured and the effects on Qo2 by transport inhibitors and metabolic substrates were studied. In eDT, complete Cl-replacement with N03 or an addition of furosemide (2 x 10 -5 M) reduced Qo2 from 8.4± 1.7 to 4.4± 0.8 or from 8.3 + 1.6 to 4.4 + 0.6 nl • min' • mg' (dry weight), respectively. Also Na + replacement with choline or with an addition to ouabain (1 x 10 -3M) reduced Qo2 from 5.9± 0.8 to 3.4± 0.4 or from 13.2± 1.8 to 4.7± 0.3 nlmin' mg' (dry weight), respectively. In PT, complete Cl -replacement with N03 or the addition of furosemide did not affect Qo2 significantly, but Na + replacement with choline or the addition of ouabain reduced it from 8.1± 1.0 to 5.4±0.7 or from 10.8±0.9 to 7.4±0.8 nl • min -' • mg -' (dry weight), respectively. The data indicate that about a half of the Qo2 in eDT is linked to active Cl-transport, in PT, Cl-is not transported actively and is not affected by furosemide. Effects on Qo2 by various metabolic substrates, including TCA-cycle intermediates and metabolizable amino acids and carboxylic acids were tested. Among them, succinate, Lglutamate, L-aspartate, citrate, and acetate were found to effectively increase the Qo2 in eDT, while lactate, pyruvate and fumarate were ineffective on Qo2. The substrate-dependencies of Qo2 in eDT were very similar to those in PT, in kinds of effective substrates and in the extent of increase. These findings suggest that, in eDT and PT, the uptake mechanisms for substrates and their coupling with aerobic metabolism are very similar.

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Section: Discussionsupporting

confidence: 68%

Dependence of oxygen consumption on Cl- transport and metabolic substrates in the early distal tubule of the Triturus kidney.

Kuramochi

1986

Jpn.J.Physiol

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“…In preliminary experiments, it was established that "4CO2 production from [ (Table I). These results closely agree with observations from other laboratories (48)(49)(50)(51)(52).…”

supporting

confidence: 83%

“…Several recent studies (49)(50)(51)(52) documented that oxidative metabolism of thick ascending limb of Henle's loop (48)(49)(50)(51)(52) is closely coupled with NaCl cotransport (48-52), a finding supported by several lines of evidence. Blocking of luminal NaCl entry into cells by loop diuretics (48)(49)(50)(51)(52) and/or removal of transported ions Na+, Cl-, or both (48)(49)(50)(51)(52), causes a marked decrease in oxidative metabolism of these epithelial cells, which is manifested and detected either as decreased oxygen consumption (49)(50)(51)(52) or decreased 14Co2 generation from '4C-labeled mitochondrial substrates (48). Our prelirninary experiments ( Table I) indeed indicated that the rate of oxidative metabolism coupled to NaCl cotransport could be assessed also in MAL microdissected from rat kidney by measuring 14CO2 formation for [14C]lactate (48).…”

supporting

confidence: 49%

Chlorpropamide action on renal concentrating mechanism in rats with hypothalamic diabetes insipidus.

Kusano¹,

Braun-Werness²,

Vick³

et al. 1983

J. Clin. Invest.

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A B S T R A C T To determine vasopressin (VP)-potentiating effect of chlorpropamide (CPMD), we studied the effect of CPMD in vivo and in vitro in kidneys and in specific tubule segments of rats with hypothalamic diabetes insipidus, homozygotes of the Brattleboro strain (DI rats). Rats on ad lib. water intake were treated with CPMD (20 mg/100 g body wt s.c. daily) for 7 d. While on ad lib. water intake, the urine flow, urine osmolality, urinary excretion of Na+, K+, creatinine, or total solute excretion did not change. However, corticopapillary gradient of solutes was significantly increased in CPMD-treated rats. Higher tissue osmolality was due to significantly increased concentration of Na+, and to a lesser degree urea, in the medulla and papilla of CPMD-treated rats. Consequently, the osmotic gradient between urine and papillary tissue of CPMD-treated rats (A = 385±47 mosM) was significantly (P < 0.001) higher compared with controls (A = 150±26 mosM). Minimum urine osmolality after water loading was higher in CPMD-treated DI rats than in controls. Oxidation of ['4C] Based on the findings recounted above, we propose a hypothesis that CPMD administration enhances the antidiuretic effect of VP, primarily by increasing medullary and papillary tonicity due to increased NaCl reabsorption in MAL. There is no evidence that CPMD sensitizes collecting tubules to the action of VP, at least at the cAMP-generation step. Therefore, increased antidiuretic response to VP in the kidneys of CPMDtreated DI rats is due to enhanced osmotic driving force for water reabsorption (lumen-to-interstitium osmotic gradient) in collecting tubules, rather than due to increased VP-dependent water permeability of tubular epithelium.

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“…Together these data indicate that mTAL of SS rats exhibit a lower rate of oxygen utilization compared with the salt-resistant SS.13 BN rats. TCA cycle substrates could not be added in these studies as was the case for isolated mitochondria respirometry studies (below) since whole mTAL cells have a limited organic acid permeability (2,11).…”

Section: Comparison Of Idh2 Activity In Mtal Mitochondria Of Ss and Smentioning

confidence: 99%

Mitochondrial proteomic analysis reveals deficiencies in oxygen utilization in medullary thick ascending limb of Henle in the Dahl salt-sensitive rat

Zheleznova

Yang

Ryan

et al. 2012

Physiological Genomics

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In the present studies we isolated mitochondria from mTAL of SS and salt-resistant control strain SS.13 BN rats on 0.4 and 8% salt diet for 7 days and performed a proteomic analysis. Purity of mTAL and mitochondria isolations exceeded 93.6 and 55%, respectively. Using LC/MS spectral analysis techniques we identified 96 mitochondrial proteins in four biological mTAL mitochondria samples, run in duplicate, as defined by proteins with a false discovery rate Ͻ5% and scan count Ն2. Seven of these 96 proteins, including IDH2, ACADM, SCOT, Hsp60, ATPA, EFTu, and VDAC2 were differentially expressed between the two rat strains. Oxygen consumption and highresolution respirometry analyses showed that mTAL cells and the mitochondria in the outer medulla of SS rats fed high-salt diet exhibited lower rates of oxygen utilization compared with those from SS.13 BN rats. These studies advance the conventional proteomic paradigm of focusing exclusively upon whole tissue homogenates to a focus upon a single cell type and specific subcellular organelle. The results reveal the importance of a largely unexplored role for deficiencies of mTAL mitochondrial metabolism and oxygen utilization in salt-induced hypertension and renal medullary oxidative stress. mitochondrial proteins; mTAL; kidney; salt-sensitive hypertension; proteomic analysis

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Biochemical and Physiological Studies on Cells Isolated From the Medullary Thick Ascending Limb of Henle's Loop

Cited by 4 publications

References 11 publications

Dependence of oxygen consumption on Cl- transport and metabolic substrates in the early distal tubule of the Triturus kidney.

Dependence of oxygen consumption on Cl- transport and metabolic substrates in the early distal tubule of the Triturus kidney.

Chlorpropamide action on renal concentrating mechanism in rats with hypothalamic diabetes insipidus.

Mitochondrial proteomic analysis reveals deficiencies in oxygen utilization in medullary thick ascending limb of Henle in the Dahl salt-sensitive rat

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