Experimental analysis of renal regulation of sodium and chloride excretion is complicated by the fact that the functional contributions of the proximal and the distal tubular segments to the urinary electrolyte pattern cannot be readily separated. If electrolyte transport in one of these tubular sites could be significantly depressed without affecting the other, it might be possible to clarify ...

Proximal tubular reabsorption was examined in patients with liver cirrhosis and ascites by a variety of indirect methods. Maximal diluting ability, urine flow rate, and free water clearance were reduced. During frusemide administration V/GFR was lower than in normal control subjects, indicating that proximal fractional reabsorption is enhanced in liver cirrhosis. This, by reducing Na delivery t...

BACKGROUND Critically ill patients in intensive care face hazardous conditions. Among these, acute kidney injury (AKI) is frequently seen as a result of sepsis. Early diagnosis of kidney injury is of the utmost importance in the guidance of interventions or avoidance of treatment-induced kidney injury. On these grounds, we searched for markers that could indicate proximal tubular cell injury. ...

NF-κB is a key regulator of innate and adaptive immunity and is implicated in the pathogenesis of acute kidney injury (AKI). The cell type-specific functions of NF-κB in the kidney are unknown; however, the pathway serves distinct functions in immune and tissue-parenchymal cells. We analyzed tubular epithelial-specific NF-κB signaling in a mouse model of ischemia-reperfusion injury (IRI)-induce...

The kidney plays an important role in the metabolism of proteins and peptides. Current evidence indicates that only the proximal tubule possesses the mechanisms for absorption, transport and/or degradation of these substances. Large proteins and polypeptide molecules filtered by the glomerulus, are absorbed from proximal tubular fluid by luminal endocytosis into apical vacuoles which fuse with ...

In this article, we describe a ratiometric intravital two-photon microscopy technique for studying glomerular permeability and differences in proximal tubule cell reabsorption. This quantitative approach is based on the Generalized Polarity (GP) concept, in which the intensity difference between two fluorescent molecules is normalized to the total intensity produced by the two dyes. After an in...

Six2cre-mediated deletion of Frs2α (Six2creFrs2αKO), a major fibroblast growth factor receptor (Fgfr) docking protein in mouse nephron progenitors results in perinatal renal hypoplasia; however, postnatal Six2creFrs2αKO kidneys develop cysts. We sought to determine the pathogenesis of Six2creFrs2αKO cyst formation. We performed histological assays, Western blots, and quantitative PCR (qPCR). Wh...

We evaluated urinary excretion and tubular transport of H-digoxin by three different methods in anesthetized rats made diuretic by infusion of 2.5% saline. In one group small volumes of H-digoxin and "C-inulin were injected simultaneously into surface proximal convolutions, and urine was collected serially from both ureters. Digoxin recovery was lower after early (62.1 ± 5.3%) than after late (...