Potassium channels in the apical and basolateral membranes of tubule cells serve several important functions. They contribute to the generation of the cell-negative potential, mediate volume reductions following cell swelling and play a key role in secretion of potassium in both the thick ascending limb of Henle's loop and principal tubule cells of the initial and cortical collecting tubules. S...

BACKGROUND In renal tubules, paracellular permeability is tightly controlled to facilitate solute absorption and urinary concentration and is regulated by tight junctions, which incorporate claudin proteins. There is very limited information confirming the localization of these proteins in the human renal cortex. Most data is inferred from mouse, bovine and rabbit studies and differences exist ...

Although intrarenal infusions of kinins produce diuresis, it is not clear to what extent this response is due to hemodynamically mediated medullary washout and/or to direct epithelial effects ofkinins. Recent evidence has shown that bradykinin binds to collecting tubules in vitro. We therefore examined the interactions of lysyl-bradykinin and antidiuretic hormone (ADH) with respect to hydraulic...

Angiotensin II plays important roles in renal vasoconstriction, sodium reabsorption in proximal tubules, and cell proliferation. Angiotensin II receptors are present not only in proximal but also in distal tubules. We investigated the effects of dehydration on the mRNA expression of type 1A angiotensin II receptor (AT1A) in proximal and distal nephron segments and on the expression of type 1 an...

Little information is available concerning the generation of renal tubules, but this information is urgently needed in regenerative medicine for the future treatment of acute and chronic renal failures. Of major interests are the integration of stem/progenitor cells, the cellular development and the tubular growth in a spatial environment. In this regard, we investigated the basal aspect of ren...

To determine whether the tissue distribution of glutathione S-transferase (GST) isoenzymes could define the precise nature of renal injury, 13 adult kidneys were studied, using specific antibodies raised against purified isoenzymes. Basic GST stained strongly proximal convoluted tubules and some medullary tubules; acidic GST stained strongly distal convoluted tubules and medullary tubules; neut...

The process of NaCl reabsorption in the distal nephron allows freshwater fishes to excrete hypotonic urine and seawater fishes to excrete urine containing high concentrations of divalent ions; the relevant transporters, however, have not yet been identified. In the mammalian distal nephron, NaCl absorption is mediated by Na(+)-K(+)-Cl(-) cotransporter 2 (NKCC2, Slc12a1) in the thick ascending l...