Renal Microperfusion
Mostrando 1-12 de 33 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 carbamazepina na reabsorção de água pelo ducto coletor medular interno de ratos normais e de ratos com diabetes insípido nefrogênico induzido pelo lítio / Effect of carbamazepine on water absorption in the inner medullary collecting duct from normal rats and from rats with lithium-induced diabetes insipidus
Carbamazepine (Carba) is an anticonvulsant and a psychotropic medication commonly used in the treatment of patients with intellectual disability (ID). This drug has been used to try to decrease the urinary volume in Diabetes Insipidus (DI) because Carba presents an antidiuretic effect, but the incidence of the hyponatremia in neurological patients is a commo
Publicado em: 2010
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3. 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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4. 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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5. Agmatine, a bioactive metabolite of arginine. Production, degradation, and functional effects in the kidney of the rat.
Until recently, conversion of arginine to agmatine by arginine decarboxylase (ADC) was considered important only in plants and bacteria. In the following, we demonstrate ADC activity in the membrane-enriched fraction of brain, liver, and kidney cortex and medulla by radiochemical assay. Diamine oxidase, an enzyme shown here to metabolize agmatine, was locali
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6. Postglomerular vascular protein concentration: evidence for a causal role in governing fluid reabsorption and glomerulotubular balance by the renal proximal tubule
We tested the relationship between postglomerular microvascular protein concentration and rates of sodium and water transfer by rat proximal tubules. Using recently described microperfusion techniques, efferent arterioles and branch peritubular capillaries of normal hydropenic rats were perfused with colloid-free Ringer's solution, and isoncotic (9.0-10.0 g/
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7. Isolated Nephron Segments from Rabbit Models of Obstructive Nephropathy
Micropuncture and microcatheterization studies have been used extensively to investigate the pathophysiologic alterations in renal function induced by urinary tract obstruction. The present isolated tubule microperfusion studies were designed to examine the intrinsic alterations in segmental nephron function induced by 24 h of bilateral (BUO) and unilateral
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8. On the Mechanism of Inhibition in Fluid Reabsorption by the Renal Proximal Tubule of the Volume-Expanded Rat
We undertook to determine the extent to which the inhibition in absolute proximal fluid reabsorption in response to expansion of extracellular volume with noncolloid-containing solutions is the result of concomitant reductions in postglomerular (efferent arteriolar) protein concentration. Selective elevation of efferent arteriolar oncotic pressure in volume-
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9. Renal NMDA receptors independently stimulate proximal reabsorption and glomerular filtration
N-methyl-d-aspartate receptors (NMDA) are expressed in the kidney, where little is known of their functional role. Several series of micropuncture experiments were performed in hydropenic rats using the NMDA channel blocker, MK801, and the NMDA coagonist, l-glycine, to probe NMDA for effects on single-nephron glomerular filtration rate (SNGFR) and proximal r
American Physiological Society.
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10. 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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11. A microperfusion study of sucrose movement across the rat proximal tubule during renal vein constriction
Constriction of the renal vein has been shown to inhibit net sodium and water reabsorption by the rat proximal tubule. The mechanism is unknown but might be the result of inhibition of the active sodium pump induced by changes in the interstitial fluid compartment of the kidney, or to enhanced passive backflux of sodium and water into the cell or directly in
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12. Sodium-coupled Taurocholate Transport in the Proximal Convolution of the Rat Kidney In Vivo and In Vitro
Using the standing droplet technique in the renal proximal convolution and simultaneous microperfusion of the peritubular capillaries, the zero net flux transtubular concentration difference of taurocholate (ΔCTC−) at 45 s was determined as a measure of active bile acid reabsorption in vivo. Starting with 0.1 mmol/liter taurocholate in both perfusates the