Loss of Cystic Fibrosis Transmembrane Regulator Impairs Intestinal Oxalate Secretion.

Patients with cystic fibrosis have an increased incidence of hyperoxaluria and calcium oxalate nephrolithiasis. Net intestinal absorption of dietary oxalate results from passive paracellular oxalate absorption as modified by oxalate back secretion mediated by the SLC26A6 oxalate transporter. We used mice deficient in the cystic fibrosis transmembrane conductance regulator gene (Cftr) to test the hypothesis that SLC26A6-mediated oxalate secretion is defective in cystic fibrosis.

Recurrent acute kidney injury following bath salts intoxication.

"Bath salts" are becoming recognized as a frequently abused and highly addictive substance that can be obtained legally in some areas. These agents contain stimulant compounds, such as methylenedioxopyrrovalerone and mephedrone, that have been associated with sympathomimetic effects and psychotic features, such as paranoia, delusions, agitation, and confusion. They may have a benign course; however, intoxication with these agents may lead to severe cardiovascular and neurologic complications and death.

A segment of gamma ENaC mediates elastase activation of Na+ transport.

The epithelial Na(+) channel (ENaC) that mediates regulated Na(+) reabsorption by epithelial cells in the kidney and lungs can be activated by endogenous proteases such as channel activating protease 1 and exogenous proteases such as trypsin and neutrophil elastase (NE). The mechanism by which exogenous proteases activate the channel is unknown. To test the hypothesis that residues on ENaC mediate protease-dependent channel activation wild-type and mutant ENaC were stably expressed in the FRT epithelial cell line using a tripromoter human ENaC construct, and protease-induced short-circuit current activation was measured in aprotinin-treated cells.

Endogenous protease activation of ENaC: effect of serine protease inhibition on ENaC single channel properties.

Endogenous serine proteases have been reported to control the reabsorption of Na(+) by kidney- and lung-derived epithelial cells via stimulation of electrogenic Na(+) transport mediated by the epithelial Na(+) channel (ENaC). In this study we investigated the effects of aprotinin on ENaC single channel properties using transepithelial fluctuation analysis in the amphibian kidney epithelium, A6. Aprotinin caused a time- and concentration-dependent inhibition (84 +/- 10.