Patricia A. Preisig

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The present study examines the role of Pyk2 in acid regulation of sodium/hydrogen exchanger 3 (NHE3) activity in OKP cells, a kidney proximal tubule epithelial cell line. Incubation of OKP cells in acid media caused a transient increase in Pyk2 phosphorylation that peaked at 30 seconds and increased Pyk2/c-Src binding at 90 seconds. Pyk2 isolated by(More)
To determine the predominant pathway for transepithelial osmotic water flow, the transepithelial osmotic water permeability [Pf(TE)] and the apparent dimensions of paracellular pores and slits were determined in rat proximal convoluted tubules microperfused in vivo. To measure Pf(TE), tubules were perfused with a hyposmotic, cyanide-containing solution.(More)
Chronic metabolic acidosis increases the activity of the proximal tubule apical membrane Na/H antiporter, which is encoded predominantly by the NHE3 isoform. The present studies examined the effect of chronic metabolic acidosis on apical membrane NHE3 protein abundance in rats. Rats subjected to NH4Cl in their drinking water developed a metabolic acidosis,(More)
The purpose of the present review is to describe the use of carbonic anhydrase inhibitors in clinical medicine and renal physiology. We first describe the localization of carbonic anhydrase within the kidney and then discuss evidence for its role in renal acidification and NaCl absorption. This is then followed by a description of clinical uses for carbonic(More)
Increased Na/H antiporter activity has been demonstrated after in vivo chronic metabolic acidosis as well as in vitro acid preincubation of cultured rabbit renal tubule cells. To study the underlying molecular mechanisms of this adaptive increase in Na/H antiporter activity, the present studies examined the effect of low pH media on Na/H antiporter activity(More)
Differences in hemodynamic stability and fluid requirements were examined in patients randomly assigned to receive either normal saline crystalloid solution (N = 10) or hetastarch colloid solution (N = 11) after coronary artery bypass or valve operation. Both solutions were administered in the same manner for 8 hours after surgery, with hourly assessment of(More)
We recently showed that, in the presence of physiological sodium concentrations, 4.3 mM luminal amiloride inhibits 90% of apical membrane Na+-H+ antiporter activity in the in vivo microperfused rat proximal convoluted tubule. In the present studies we examined the effect of 4.3 mM luminal amiloride on transepithelial NaCl absorption from a high-chloride,(More)
BACKGROUND Two mechanisms exist for inducing renal proximal tubule hypertrophy. One is characterized by regulation of the G1 cell cycle kinase (cell cycle-dependent mechanism), while the other mechanism involves an imbalance between rates of protein synthesis and degradation, and occurs independently of cell cycle kinase regulation (cell cycle-independent(More)
This review focuses on the basolateral membrane mechanisms of H-OH-HCO3 transport in the proximal tubule. The mechanism that has the greatest transport capacity and mediates most of transepithelial H-HCO3 transport is the electrogenic, Na-3HCO3 cotransporter. This transporter has been extensively characterized in the salamander, rat, and rabbit proximal(More)