Accelerated reabsorption in the proximal tubule produced by volume depletion

Accelerated reabsorption in the proximal tubule produced by volume depletion.

The renal response to chronic depletion of extracellular volume was examined using the techniques of micropuncture. Depletion of salt and water was produced by administration of furosemide to rats maintained on a sodium-free diet. There was a marked fall in body weight, plasma volume, and glomerular filtration rate. The intrinsic reabsorptive capacity of the proximal tubule, measured by the spl...

Isosmotic volume reabsorption in rat proximal tubule

A theoretical model incorporation both active and passive forces has been developed for fluid reabsorption from split oil droplets in rat intermediate and late proximal tubule. Of necessity, simplifying assumptions have been introduced; we have assumed that the epithelium can be treated as a single membrane and that the membrane "effective" HCO3 permeability is near zero. Based on this model wi...

Factors affecting sodium reabsorption by the proximal tubule as determined during blockade of distal sodium reabsorption.

Changes in the tubular reabsorption of sodium independent of aldosterone activity may play an important role in determining sodium excretion. Several studies in the dog employing clearance techniques have demonstrated that infusions of isotonic saline (1-5) or plasma-like solutions (1, 2) result in a depression of the over-all net tubular reabsorption of sodium as the excretion of sodium increa...

Model of albumin reabsorption in the proximal tubule.

Normally, the small amount of albumin which passes through the glomerular capillary wall is almost completely reabsorbed in the proximal tubule, via an endocytic mechanism, but the reabsorptive process can be overwhelmed if the filtered load of albumin is too large. To examine the factors that control the fractional reabsorption of albumin (f), we developed a mathematical model which assumes sa...

Potassium reabsorption in the proximal tubule of the dog nephron.