Related Experiment Video
Updated: Aug 10, 2026

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model
Published on: June 29, 2014
Influence of aortic constriction on proximal chloride reabsorption during volume expansion
Abstract:
Extracellular fluid volume expansion is associated with a decrease in the transepithelial chloride gradient in the proximal convoluted tubule. We have previously shown that this effect occurs in the presence of hypo- or hyperchloremia and is not dependent on a change in filtered chloride or bicarbonate load. To determine the influence of filtered fluid load on this effect of volume expansion, micropuncture studies were carried out during acute extracellular fluid volume expansion in rats with (group AC) and without (group CON) a reduction in renal perfusion pressure. Delayed aortic constriction prevented the increase in fluid load (49.7 +/- 2.4 and 49.0 +/- 3.9 nl/min for hydropenia and volume expansion, respectively), but reduced tubule fluid to plasma inulin ratios (2.25 +/- 0.13 and 1.84 +/- 0.8) were maintained. Tubule fluid to plasma chloride ratios did not change in group AC (1.27 +/- 0.03 and 1.25 +/- 0.01) as compared to group CON (1.25 +/- 0.02 and 1.18 +/- 0.02; p less than 0.05). Fractional chloride reabsorption fell in both groups. Absolute chloride reabsorption was highly correlated (p less than 0.001) with absolute fluid reabsorption. These results suggest that filtered fluid load or some related variable is an important determinant of the generation of the chloride gradient in the proximal tubule.
Related Concept Videos
Antihypertensive Drugs: Angiotensin II Receptor Blockers
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
Reabsorption and Secretion in the Loop of Henle
Reabsorption and Secretion in the DCT and Collecting Duct
The distal part of the DCT, along with the...
Formation of Concentrated Urine
Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion

