Bicarbonate Reabsorption
Mostrando 1-12 de 86 artigos, teses e dissertações.
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1. Efeitos não-genômicos dos hormônios esteróides - aldosterona e corticosterona - sobre a acidificação do túbulo proximal (S2) de ratos: estudos de microperfusão tubular e capilar, in vivo . / Nongenomic effect of steroid hormones - aldosterone and corticosterone - on acidification of rat proximal tubule (S2) studies by tubular and capillary microperfusion, in vivo .
The purpose was to determine if aldosterone and corticosterone act on the acidification of proximal tubule and if these hormonal effects are genomic and/or nongenomic. Bicarbonate reabsorption was evaluated by microperfusion. Aldosterone and corticosterone caused a significant increase in JHCO3-. In the presence of ethanol, actinomycin D, cycloheximide or es
Publicado em: 2010
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2. Efeito da uroguanilina sobre o transporte de hidrogênio em túbulos renais de rins de rato e em linhagens de células proximais e distrais / Effect of Uroguanylin on hydrogen transport in rat renal tubules and in proximal and distal cells lines
Uroguanilina (UGN) é um peptídeo normalmente sintetizado no intestino que modula o balanço de sódio através de ações renais. Investigamos os efeitos e os mecanismos de sinalização envolvidos na ação da UGN sobre a secreção de H+, em túbulos renais de ratos e em células LLC-PK1 (proximais) e MDCK-C11 (distais). Nos estudos in vivo foi utilizada
Publicado em: 2009
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3. Effects of Glucose on Bicarbonate Reabsorption in the Dog Kidney
The effects of glucose on renal bicarbonate reabsorption were investigated in the dog. The infusion of small amounts of glucose calculated to slightly exceed the renal threshold for glucose absorption increased bicarbonate reabsorption in bicarbonate loaded dogs. Galactose in similar doses also increased the reabsorption of filtered bicarbonate. This effect
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4. Renal bicarbonate reabsorption in the rat. III. Distal tubule perfusion study of load dependence and bicarbonate permeability.
Using continuous microperfusion techniques, we studied the load dependence of bicarbonate reabsorption along cortical distal tubules of the rat kidney and their bicarbonate permeability. Net bicarbonate transport was evaluated from changes in tracer inulin concentrations and total CO2 measurements by microcalorimetry. Bicarbonate permeability was estimated f
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5. Renal bicarbonate reabsorption in the rat. II. Distal tubule load dependence and effect of hypokalemia.
We studied two groups of rats acutely loaded with bicarbonate, control rats on a standard diet and rats kept on a K-free diet for 3 wk. Compared with controls, K-depleted rats had reduced fractional excretion of bicarbonate despite their elevated filtered bicarbonate load. Distal bicarbonate reabsorption increased in K-depleted rats. In the presence of almos
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6. Effect of carbonic anhydrase inhibition on superficial and deep nephron bicarbonate reabsorption in the rat.
The nephron segment responsible for the acetazolamide-insensitive fraction of renal bicarbonate reabsorption has not been clearly delineated. This study compares superficial and deep nephron bicarbonate reabsorption before and after acetazolamide at two dose levels (20 and 50 mg/kg per h) in mutant Munich-Wistar rats employing both cortical and papillary mic
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7. On the influence of extracellular fluid volume expansion and of uremia on bicarbonate reabsorption in man
The patterns of bicarbonate reabsorption during increasing plasma concentrations were studied in subjects with a range of glomerular filtration rates (GFR) from 170 to 2 ml/min. In a group of five subjects with GFR values above 30 ml/min, paired bicarbonate titration studies were performed first under conditions which minimized extracellular fluid (ECF) volu
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8. On the influence of extracellular fluid volume expansion on bicarbonate reabsorption in the rat
Bicarbonate reabsorption is classically regarded as a rate-limited process characterized by saturation kinetics. The tubular maximum (Tm), however, varies with glomerular filtration rate. Thus bicarbonate reabsorption, in common with sodium reabsorption, is characterized by glomerulo-tubular balance. The examination of bicarbonate reabsorption is accomplishe
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9. Augmented bicarbonate reabsorption by both the proximal and distal nephron maintains chloride-deplete metabolic alkalosis in rats.
Whether augmented bicarbonate reabsorption by renal tubular epithelium contributes to the maintenance of chloride-deplete metabolic alkalosis is not clear. This study used free-flow micropuncture to investigate bicarbonate reabsorption by surface nephron segments in a rat model of diuretic-induced alkalosis compared to control. The proximal and distal nephro
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10. Proximal tubular bicarbonate reabsorption and PCO2 in chronic metabolic alkalosis in the rat.
Studies were undertaken to define the pattern of proximal tubular bicarbonate reabsorption and its relation to tubular and capillary PCO2 in rats with chronic metabolic alkalosis (CMA). CMA was induced by administering furosemide to rats ingesting a low electrolyte diet supplemented with NaHCO3 and KHCO3. Proximal tubular bicarbonate reabsorption and PCO2 we
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11. Renal bicarbonate reabsorption in the rat. I. Effects of hypokalemia and carbonic anhydrase.
Free-flow micropuncture studies were carried out on superficial rat proximal and distal tubules to assess the participation of different nephron segments in bicarbonate transport. Particular emphasis was placed on the role of the distal tubule, and micro-calorimetric methods used to quantitate bicarbonate reabsorption. Experiments were carried out in control
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12. Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats
This free-flow micropuncture study examined the dependence of bicarbonate reabsorption in the rat superficial proximal convoluted tubule to changes in filtered bicarbonate load, and thereby the contribution of the proximal tubule to the whole kidney's response to such changes. The independent effects of extracellular fluid (ECF) volume expansion and of acido