Jhco3
Mostrando 1-12 de 13 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. Effect of D-alpha-tocopherol on tubular nephron acidification by rats with induced diabetes mellitus
The objective of the present study was to determine if treatment of diabetic rats with D-alpha-tocopherol could prevent the changes in glomerular and tubular function commonly observed in this disease. Sixty male Wistar rats divided into four groups were studied: control (C), control treated with D-alpha-tocopherol (C + T), diabetic (D), and diabetic treated
Brazilian Journal of Medical and Biological Research. Publicado em: 2005-07
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3. Effects of osmolality on bicarbonate absorption by medullary thick ascending limb of the rat.
Previously we demonstrated that arginine vasopressin (AVP) directly inhibits bicarbonate absorption (JHCO3, pmol/min per mm) in the medullary thick ascending limb (MTAL) of the rat. To determine whether changes in osmolality also may affect bicarbonate absorption, MTAL were studied in vitro with 25 mM HCO3- solutions. Control osmolality was 290 mosmol/kg H2O
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4. Bicarbonate transport along the loop of Henle. I. Microperfusion studies of load and inhibitor sensitivity.
We microperfused the loop of Henle (LOH) to assess its contribution to urine acidification in vivo. Under control conditions (Na HCO3- = 13 mM, perfusion rate approximately 17 nl/min-1) net bicarbonate transport (JHCO3-) was unsaturated, flow- and concentration-dependent, and increased linearly until a bicarbonate load of 1,400 pmol.min-1 was reached. Methaz
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5. Basolateral membrane Na+/H+ exchange enhances HCO3- absorption in rat medullary thick ascending limb: evidence for functional coupling between basolateral and apical membrane Na+/H+ exchangers.
The role of basolateral membrane Na+/H+ exchange in transepithelial HCO3- absorption (JHCO3) was examined in the isolated, perfused medullary thick ascending limb (MTAL) of the rat. In Na(+)-free solutions, addition of Na+ to the bath resulted in a rapid, amiloride-sensitive increase in intracellular pH. In MTALs perfused and bathed with solutions containing
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6. Anion dependence of rabbit medullary collecting duct acidification.
Rabbit medullary collecting duct (MCD) acidification has been demonstrated to occur by means of a sodium-independent, aldosterone-stimulated mechanism. We have examined the anionic dependence of this process by means of the isolated perfused tubule technique. Total replacement of perfusate chloride with gluconate enhanced tubular bicarbonate reabsorption (JH
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7. Bicarbonate transport along the loop of Henle. II. Effects of acid-base, dietary, and neurohumoral determinants.
The loop of Henle contributes to renal acidification by reabsorbing about 15% of filtered bicarbonate. To study the effects on loop of Henle bicarbonate transport (JHCO3) of acid-base disturbances and of several factors known to modulate sodium transport, these in vivo microperfusion studies were carried out in rats during: (a) acute and chronic metabolic ac
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8. Evidence from renal proximal tubules that \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{HCO}}_{3}^{-}\end{equation*}\end{document} and solute reabsorption are acutely regulated not by pH but by basolateral \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{HCO}}_{3}^{-}\end{equation*}\end{document} and CO2
Respiratory acidosis, a decrease in blood pH caused by a rise in [CO2], rapidly triggers a compensatory response in which the kidney markedly increases its secretion of H+ from blood to urine. However, in this and other acid-base disturbances, the equilibrium CO2 + H2O ⇄ \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{a
National Academy of Sciences.
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9. Chloride and bicarbonate transport in fetal red cells.
1. Chloride (JCl) and bicarbonate (JHCO3) self-exchange flux in fetal human red cells was studied at 0-38 degrees C as 36Cl- and [14C]HCO3- efflux. 2. Both at 0 and 38 degrees C JCl showed a bell-shaped pH dependence with a broad maximum at pH 7-8. JCl was 99.7% inhibited by the binding of 1.1 x 10(6) 4,4'-diisothiocyanostilbene-2,2'-disulphonate (DIDS) mole
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10. Intestinal bicarbonate secretion in Amphiuma measured by pH stat in vitro: relationship with metabolism and transport of sodium and chloride ions.
1. Isolated Amphiuma small intestine exposed on both surfaces to buffered or unbuffered media generated gradients of pH under short-circuited conditions consistent with secretion of HCO3(-). 2. When unbuffered mucosal medium was maintained at pH 7.4 by addition of acid, alkalinization of the mucosal medium occurred at a rate of 1-2 microequiv/hr cm2 under sh
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11. A functional CFTR protein is required for mouse intestinal cAMP-, cGMP- and Ca(2+)-dependent HCO3- secretion.
1. Most segments of the gastrointestinal tract secrete HCO3-, but the molecular nature of the secretory mechanisms has not been identified. We had previously speculated that the regulator for intestinal electrogenic HCO3- secretion is the cystic fibrosis transmembrane regulator (CFTR) channel. To prove this hypothesis, we have now measured HCO3- secretion by
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12. Kinetic properties and Na+ dependence of rheogenic Na(+)-HCO3- co-transport in frog retinal pigment epithelium.
1. Na(+)-HCO3- co-transport across the retinal membrane of the frog retinal pigment epithelium was studied by means of double-barrelled pH-selective microelectrodes. Transient changes in the intracellular pH were monitored in response to abrupt changes in the Na+ concentration on the retinal side of the epithelium. 2. The experiments were performed as follow