Renal sodium reabsorption following induction of recovery from volume expansion

1977 ◽  
Vol 233 (5) ◽  
pp. F416-F420
Author(s):  
T. F. Knight ◽  
E. J. Weinman
Keyword(s):  
Urinary Excretion ◽  
Proximal Tubule ◽  
Volume Expansion ◽  
Isotonic Saline ◽  
Extracellular Fluid ◽  
Recovery Phase ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Renal Sodium Reabsorption ◽  
Distal Delivery

In the rat, infusion of a volume of isotonic saline equal to 2% of body weight resulted in an 82% increase in delivery of filtrate out of the proximal tubule but little or, in some animals, no change in the urinary excretion of sodium. By contrast, further degrees of volume expansion resulted in lesser increases in the distal delivery of filtrate, but were associated with a marked increase in the urinary excretion of sodium. Sixty minutes following completion of volume expansion, while the animals were still in positive sosium balance, the urinary excretion of sodium decreased 52% compared to a decrease of only 24% in the distal delivery of filtrate. During the course of progressive volume expansion and during the recovery phase, there was a dissociation between alterations in sodium reabosrption in the proximal convoluted tubule and in the whole kidney. These studies indicate that although the proximal tubule is more sensitive to changes in the extracellular fluid volume, distal nephron sites are ultimately responsible both for the natriuresis of volume expansion and the relative antinatriuresis of the recovery periods.

Single-nephron function and renal oxygen consumption during rapid volume expansion

1976 ◽  
Vol 231 (4) ◽  
pp. 1166-1172 ◽  
Author(s):  
SW Weinstein ◽  
J Szyjewicz
Keyword(s):  
Oxygen Consumption ◽  
Proximal Tubule ◽  
Volume Expansion ◽  
Ringer Solution ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Renal Oxygen Consumption ◽  
Single Nephron ◽  
Proximal Tubular ◽  
Renal Sodium Reabsorption

Isotonic volume expansion reduces net filtrate reabsorption in the proximal tubule while increasing it in Henle's loop. To determine the role oxidative metabolism plays in these processes, experiments were performed on rats initially hydropenic and then rapidly volume expanded with isotonic Ringer solution. Whole-kidney sodium reabsorption, oxygen consumption, and single-nephron function were measured simultaneously. During volume expansion, net renal sodium reabsorption increased concomitantly with a fall in oxygen consumption and a reduction in proximal tubular absolute filtrate reabsorption. The increase in quantity of nonreabsorbed filtrate delivered into the loop of Henle greatly exceeded the amount excreted in the urine. Thus, filtrate reabsorption by the distal nephron segments increased. These data provide evidence that acute volume expansion reduces oxygen-dependent active solute transport in the proximal tubule. The increase noted in distal nephron sodium reabsorption appears nonoxygen dependent, energized by anaerobic glycolysis or occurring passively.

Quantitative relationship of renal glucose and sodium reabsorption during ECF expansion

1975 ◽  
Vol 229 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Higgins JT ◽  
AE Meinders
Keyword(s):  
Proximal Tubule ◽  
Isotonic Saline ◽  
Extracellular Fluid ◽  
Quantitative Relationship ◽  
Ringer Solution ◽  
Sodium Balance ◽  
Sodium Reabsorption ◽  
Coupled Transport ◽  
Appearance Time ◽  
Glucose Reabsorption

To investigate the quantitative relationship between glucose and sodium reabsorption during extracellular fluid (ECF) expansion and to examine the possible contribution to glucosuria of passive diffusion of glucose from peritubular blood to tubular fluid, renal clearance studies were carried out in dogs. It was found that ECF expansion with isotonic saline or Ringer solution causes a decrease in the maximal rate of glucose reabsorption (TmGlc), which is inversely and linearly related to fractional sodium excretion (FENa) over a range from less than 1% more than 25% FENa (r equals -0.394, P less than 0.001). A continuous relationship between TmGlc and FENa could be demonstrated as the ECF was expanded in individual animals as well as in pooled data. Infusion of albumin solution to preferentially expand the plasma volume and decrease proximal tubular sodium reabsorption produced a 24% fall in TmGlc suggesting that the proximal tubule is the site of interrelated glucose and sodium reabsorption. After pulse injections into the renal artery, [14-C]glucose and insulin had the same appearance time in the urine, thus failing to demonstrate diffusion of glucose from blood into the tubule in saline-loaded dogs as well as in dogs in normal sodium balance. It is suggested that ECF expansion exerts its effect on glucose reabsorption by inhibiting the coupled transport of glucose and sodium across the epithelium of the renal proximal tubule.

Influence of Volume Expansion on Renal Diluting Capacity in the Rat

1974 ◽  
Vol 46 (3) ◽  
pp. 331-345
Author(s):  
M. Martinez-Maldonado ◽  
G. Eknoyan ◽  
W. N. Suki
Keyword(s):  
Volume Expansion ◽  
Collecting Duct ◽  
Isotonic Saline ◽  
Extracellular Fluid ◽  
Free Water ◽  
Fluid Volume ◽  
Extracellular Fluid Volume ◽  
Sodium Reabsorption ◽  
Water Excretion ◽  
Hypotonic Saline

1. The functional capacity of Henle's loop was examined during hypotonic, isotonic and hypertonic extracellular fluid volume expansion. To eliminate a possible role of antidiuretic hormone (ADH) in the alteration of free water excretion, rats with congenital diabetes insipidus were used. The infusion of hypotonic saline resulted in a progressive rise in free water clearance (CH2O) throughout the range of urine flow (V) attained. Similar results were obtained in rats treated chronically with deoxycorticosterone acetate (DOCA). The infusion of isotonic saline (sodium chloride, 154 mmol/l) produced an initial rise in CH2O until V represented 10% of the filtered load, after which CH2O appeared to reach a plateau. The limitation of CH2O was more marked when hypertonic saline was infused. Medullary and papillary non-urea solute (NUS) concentration rose progressively with the increasing concentration of the saline solution infused. 2. The greater fractional sodium excretion (FENa) after acute isotonic and hypertonic volume expansion is probably the result of inhibition of sodium reabsorption in the collecting duct, although inhibition in the ascending limb cannot be entirely excluded. The depression of CH2O as a function of V seen during acute isotonic or hypertonic volume expansion can be attributed in part to enhanced water back-diffusion from the collecting duct consequent to the increasing medullary and papillary interstitial NUS concentration, even in the absence of ADH. 3. Chronic expansion of extracellular fluid volume by DOCA administration did not modify the response to hypotonic saline infusion.

Chloride-depletion alkalosis with a normal extracellular fluid volume

1983 ◽  
Vol 245 (4) ◽  
pp. F419-F424
Author(s):  
R. G. Luke ◽  
J. H. Galla
Keyword(s):  
Volume Expansion ◽  
Collecting Duct ◽  
Extracellular Fluid ◽  
Limited Capacity ◽  
Distal Nephron ◽  
Chloride Depletion ◽  
Chloride Salts ◽  
Distal Convolution ◽  
Sodium And Potassium ◽  
Permissive Role

Current concepts hold that volume expansion is essential to the correction of chloride-depletion alkalosis (CDA) with chloride repletion in a permissive role. In this scheme, intranephronal fluid reabsorption would be redistributed with increased delivery to the distal nephron where the provided chloride is readily reabsorbed and the limited capacity for bicarbonate reabsorption would promote bicarbonate excretion and correction of CDA. In a model of CDA produced by peritoneal dialysis against 0.15 M NaHCO3, we have shown complete correction of CDA within 24 h without volume expansion by either oral isotonic sodium or chloride salts with 70 mM chloride and despite an obligatory bicarbonate load and negative sodium and potassium balance. During correction of CDA without volume expansion in rats by intravenous isotonic fluids containing 80 mM chloride, fractional fluid and chloride reabsorptions in the proximal convoluted tubule and in the loop segment of superficial nephrons were not different from controls but chloride reabsorption was enhanced in the collecting duct segment and probably within the distal convolution. Despite no differences in serial hematocrits, blood pressure, and measured plasma volume, kidney and nephron glomerular filtration rate (GFR) were reduced in CDA and returned to normal upon recovery 24 h later.(ABSTRACT TRUNCATED AT 250 WORDS)

RENAL RESPONSE TO INFUSION OF ISOTONIC RINGER-LOCKE SOLUTION: EFFECT OF HYPOPHYSECTOMY

1977 ◽  
Vol 74 (2) ◽  
pp. 193-204
Author(s):  
J. T. BAKER ◽  
S. SOLOMON
Keyword(s):  
Body Weight ◽  
Proximal Tubule ◽  
Volume Expansion ◽  
Extracellular Fluid ◽  
Fluid Volume ◽  
Extracellular Fluid Volume ◽  
Water Reabsorption ◽  
Locke Solution ◽  
Hypophysectomized Rats ◽  
Distal Tubules

A comparison of the renal response to extracellular fluid volume expansion (5% body weight) was made between 25 normal and 25 chronically hypophysectomized rats. The extracellular fluid compartments averaged 25 ± 1% of body weight in both groups during control, fasted conditions. Extracellular fluid volume increased to 33 ± 1% in hypophysectomized and 34 ± 2% in normal rats during expansion, based on body weight. In addition, filtration fraction was similar in both normal and hypophysectomized rats during control (0·29 ± 0·03 and 0·26 ± 0·02 respectively) and infusion of Ringer–Locke solution (0·24 ± 0·05 and 0·27 ± 0·05 respectively). Thus our results cannot be explained by differences in the degree of expansion or failure to increase filtration in proportion to plasma flow. During infusion of isotonic Ringer–Locke solution, fractional water and sodium excretion both averaged 5·1% in normal rats and only 1·3% and 0·82% respectively in hypophysectomized rats. The ratio of single nephron to whole kidney filtration rate failed to increase as much in hypophysectomized compared with normal rats. Significant increases of fractional volume excretion occurred in both groups by the end of the accessible portion of the proximal tubule. However, fractional water reabsorption was depressed significantly more in normal (mean = 37%) than in hypophysectomized rats (mean = 19%). Fractional water reabsorption in distal tubules was similar in both groups during expansion. Arterial pressure was lower in hypophysectomized rats under control conditions, but showed similar changes during expansion compared with normal rats. Passage time decreased significantly in all groups after Ringer–Locke infusion, but remained prolonged in hypophysectomized rats in proximal and distal tubules. It is concluded that chronic hypophysectomy results in a less efficient renal excretion of volume and sodium chloride load. This inefficiency appears to be related in part to (1) failure of the proximal tubule to depress water reabsorption to a level equivalent to normal rats, and (2) failure to re-distribute flow to outer cortical glomeruli following extracellular fluid volume expansion in hypophysectomized rats.

Influence of Hydrostatic and Oncotic Pressure on Sodium Reabsorption in the Unilateral Pyelonephritic Dog Kidney

1974 ◽  
Vol 47 (4) ◽  
pp. 367-376
Author(s):  
J. P. Wagnild ◽  
F. D. Gutmann ◽  
R. E. Rieselbach
Keyword(s):  
Sodium Chloride ◽  
Volume Expansion ◽  
Extracellular Fluid ◽  
Sodium Reabsorption ◽  
Oncotic Pressure ◽  
Peritubular Capillary ◽  
Physical Force ◽  
Dog Kidney ◽  
Capillary Fluid ◽  
Diseased Kidney

1. The diseased kidney in the dog with experimental unilateral reduction in nephron population, has been shown previously to undergo an exaggerated inhibition of sodium reabsorption after extracellular fluid (ECF) volume expansion induced by isotonic sodium chloride solution compared with the control kidney. The latter serves to maintain a non-azotaemic environment. 2. In the present studies, manoeuvres designed to alter predominantly either post-glomerular hydrostatic pressure (PGHP) or peritubular capillary oncotic pressure (COP) were performed to investigate further the mechanism of this exaggerated natriuresis. 3. Volume expansion with 5 g/dl albumin in 145 mmol/l sodium chloride (saline), thereby increasing PGHP without changing COP, produced exaggerated diseased kidney natriuresis, but of a smaller magnitude than when the same dogs were studied under a lesser degree of intravascular volume expansion with 145 mmol/l saline. Renal vasodilatation produced by systemically administered dopamine, which increases PGHP without ECF volume expansion, also produced exaggerated natriuresis by the diseased kidney. 4. A selective decrease in COP induced by expansion with saline in conjunction with trimethophan camsylate (Arfonad)-induced hypotension also produced exaggerated diseased kidney natriuresis, but to a lesser degree than saline expansion alone in the same dogs. 5. Thus experimental manoeuvres designed to reduce peritubular capillary fluid reabsorption by either predominantly increasing PGHP or decreasing COP produced exaggerated diseased kidney natriuresis. This exaggerated natriuretic response to manoeuvres which predominantly altered either physical force by itself did not approach the response elicited by expansion with saline. 6. The data suggest that alterations in Starling forces play an important role in mediating the exaggerated diseased kidney natriuresis after an acute saline load.

Suppressive action of prolactin on renal response to volume expansion

1975 ◽  
Vol 229 (1) ◽  
pp. 81-85 ◽  
Author(s):  
MS Lucci ◽  
HH Bengele ◽  
S Solomon
Keyword(s):  
Volume Expansion ◽  
Isotonic Saline ◽  
Sodium Reabsorption ◽  
Physical Factors ◽  
Water Load ◽  
Renal Response ◽  
Water Handling ◽  
Male Wistar Rats ◽  
Diuretic Response ◽  
Ovine Prolactin

The effects of prolactin on rat renal sodium and water handling during volume expansion were studied using clearance techniques. Both control and experimental adult male Wistar rats were prehydrated with an oral water load of volume equal to 2.5% body weight (BW). At least 3 h later, a continuous intravenous infusion of ovine prolactin (NIH-P-S8), 7.1 mug/h per 100 g, was started in the experimental group. After a 1-h steady-state period, the rats were given an intravenous expansion infusion of either hypotonic saline (2.5% BW), isotonic saline (2.5% and 7.5% BW), or blood (2.5% BW). In all control hypotonic and isotonic saline-expanded animals, within 1 h the rats excreted a volume of urine equal to over 50% of the volume of saline infused. The diuretic and natriuretic responses to saline expansion of prolactin-treated rats were significantly smaller than controls. In contrast to the effects of prolactin on the renal response to saline infusions, it did not alter the natriuretic or diuretic response to blood infusion. Prolactin may be counteracting the effects of physical factors on the regulation of sodium reabsorption in the proximal tubule.

Isotonic saline causes greater volume overload than electrolyte-free irrigating fluids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert G. Hahn
Keyword(s):  
Urinary Excretion ◽  
Plasma Volume ◽  
Volume Expansion ◽  
Isotonic Saline ◽  
Volume Overload ◽  
Systemic Absorption ◽  
Free Fluid ◽  
Plasma Volume Expansion ◽  
Pooled Data ◽  
Elimination Half

Abstract Objectives Systemic absorption of the irrigating fluid used to flush the operating site is a potentially serious complication in several types of endoscopic operations. To increase safety, many surgeons have changed from a monopolar to a bipolar resection technique because 0.9% saline can then be used instead of electrolyte-free fluid for irrigation. The present study examines whether the tendency for excessive plasma volume expansion is greater with saline than with electrolyte-free fluid. Methods Pooled data were analyzed from four studies in which a mean of 1.25 L of either 0.9% saline or an electrolyte-free irrigating fluid containing glycine, mannitol, and sorbitol was given by intravenous infusion on 80 occasions to male volunteers and patients scheduled for transurethral prostatic surgery. The distribution of the infused fluid was analyzed with a population volume kinetic model based on frequently measured hemodilution and the urinary excretion. Results Electrolyte-free fluid distributed almost twice as fast and was excreted four times faster than 0.9% saline. The distribution half-life was 6.5 and 10.6 min for the electrolyte-free fluid and saline, respectively, and the elimination half-lives (by urinary excretion) from the plasma volume were 21 and 87 min. Simulation showed that the plasma volume expansion was twice as great from 0.9% saline than from electrolyte-free fluid. Conclusions Isotonic (0.9%) saline expands the plasma volume by twice as much as occurs with electrolyte-free irrigating fluids. This difference might explain why signs of cardiovascular overload are the most commonly observed adverse effects when saline is absorbed during endoscopic surgery.

Exaggerated Phosphaturic Response to Volume Expansion in Patients with Essential Hypertension

1975 ◽  
Vol 49 (3) ◽  
pp. 207-211 ◽  
Author(s):  
C. Chaimovitz ◽  
A. Spierer ◽  
H. Leibowitz ◽  
S. Tuma ◽  
O. S. Better
Keyword(s):  
Volume Expansion ◽  
Chloride Solution ◽  
Sodium Reabsorption ◽  
Water Diuresis ◽  
Diluting Segment ◽  
Hypertensive Patients ◽  
Reabsorptive Capacity ◽  
Proximal Tubular ◽  
Isotonic Sodium Chloride ◽  
Distal Delivery

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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