Integrating Effects of Aquaporins, Vasopressin, Distal Delivery of Filtrate and Residual Water Permeability on the Magnitude of Water Diuresis

1. Tubular handling of sodium in hypertensive patients has been evaluated with urinary phosphate excretion used as a marker for proximal tubular reabsorptive capacity. 2. Nine hypertensive patients and nine normal control subjects were studied during sustained water diuresis and the intravenous infusion of isotonic sodium chloride solution to produce volume expansion. 3. In the hypertensive patients there was exaggerated phosphaturia, natriuresis and enhanced distal delivery of sodium. Sodium reabsorption in the diluting segment was normal. 4. The enhanced distal delivery and augmented phosphaturia suggest that a decreased reabsorption of sodium in the proximal tubule is the most likely explanation for the exaggerated natriuretic response to volume expansion in hypertensive patients.

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The Effect of Acute Extracellular Volume Expansion on Sodium Chloride Reabsorption in the Diluting Segment in Man

Clinical Science ◽

10.1042/cs0540333 ◽

1978 ◽

Vol 54 (3) ◽

pp. 333-336

Author(s):

N. Ish-Shalom ◽

J. Rapoport ◽

C. Chaimovitz ◽

O. S. Better

Keyword(s):

Glomerular Filtration Rate ◽

Sodium Chloride ◽

Volume Expansion ◽

Filtration Rate ◽

Extracellular Volume ◽

Free Water ◽

Water Diuresis ◽

Water Formation ◽

Extracellular Volume Expansion ◽

Distal Delivery

1. The effect of extracellular volume expansion (ECVE) during water diuresis, and of water diuresis alone, on the formation of free water in man was compared. 2. ECVE reduced free water formation at any given rate of distal delivery compared with water diuresis. Thus, ECVE depresses distal sodium chloride reabsorption. 3. This attenuation of free water formation occurred both when urine flow (V/100 ml glomerular filtration rate) and distal chloride delivery [(Cwater + CCl)/100 ml glomerular filtration rate] were used as the terms for distal delivery. 4. We suggest that the distal depression of sodium chloride reabsorption after ECVE is probably due to a direct inhibition of distal sodium chloride transport mechanisms, and not to the flooding of the diluting site by the poorly reabsorbable bicarbonate ion.

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Deinking of recycled paper by coupling of the enzyme endo-β-1,4-D-glucanasa and the cellulose, and by using a laboratory flotation column

MRS Advances ◽

10.1557/adv.2020.390 ◽

2020 ◽

Vol 5 (52-53) ◽

pp. 2669-2678

Author(s):

Jeovani González P. ◽

Ramiro Escudero G

Keyword(s):

Amino Acids ◽

Sodium Hydroxide ◽

Paper Industry ◽

Computational Simulation ◽

Cellulose Fibers ◽

Residual Water ◽

Chemical Reagent ◽

Recycled Paper ◽

Flotation Column ◽

Hydrolysis Of

AbstractDeinking of recycled office (MOW) paper was carried out by using a flotation column and adding separately sodium hydroxide, and the enzyme Cellulase Thricodema Sp., as defibrillators.The de-inked cellulose fibers were characterized according to the standards of the paper industry, to compare the efficiency of the deinking of each chemical reagent used to hydrolyze the fibers and defibrillate them.The computational simulation of the molecular coupling between the enzyme and cellulose was performed, to establish the enzyme-cellulose molecular complex and then to identify the principal amino-acids of endo-β-1,4-D-glucanase in this molecular link, which are responsible for the hydrolysis of the cellulose.Experimental results show the feasibility to replace sodium hydroxide with the enzyme Cellulase Thricodema Sp., by obtaining deinked cellulose with similar optical and physical properties.The use of the enzyme instead of sodium hydroxide avoids the contamination of the residual water; in addition to that, the column is operated more easily, taking into consideration that the pH of the system goes from alkaline to neutral.

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