Modification of feedback influence on glomerular filtration rate by acute isotonic extracellular volume expansion

1979 ◽  
Vol 381 (2) ◽  
pp. 99-105 ◽  
Author(s):  
A. Erik G. Persson ◽  
J�rgen Schnermann ◽  
Fred S. Wright
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Volume Expansion ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Extracellular Volume Expansion

Measurement of glomerular filtration rate in conscious unrestrained rats with inulin infused by implanted osmotic pumps

1985 ◽  
Vol 248 (5) ◽  
pp. F734-F738 ◽  
Author(s):  
J. Jobin ◽  
J. P. Bonjour
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Food Consumption ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Normal Fluid ◽  
Osmotic Minipumps ◽  
Extracellular Volume Expansion ◽  
Pump Implantation

A method is described for determining glomerular filtration rate (GFR) in conscious unrestrained rats without extracellular volume expansion. The glomerular marker used was 14C-labeled inulin infused in the minimal fluid volume of 1 microliter/h by intraperitoneally implanted osmotic minipumps. The workability, reproducibility, and precision of the technique was evaluated in sham-operated (sham) and uninephrectomized (UNI-NX) rats for 6 days. In six sham-operated rats the clearance of [14C]-inulin calculated from the plasma value obtained in a blood sample taken at 10 A.M. before food consumption was (means +/- SE): day 1 after pump implantation: 1.38 +/- 0.05; day 2: 1.27 +/- 0.05; day 3: 1.46 +/- 0.16; day 4: 1.45 +/- 0.15; day 5: 1.33 +/- 0.08; day 6: 1.38 +/- 0.11 ml/min. In six UNI-NX rats the corresponding values were: day 1: 0.88 +/- 0.04; day 2: 0.79 +/- 0.05; day 3: 0.91 +/- 0.03; day 4: 0.91 +/- 0.03; day 5: 0.83 +/- 0.06; day 6: 0.87 +/- 0.05 ml/min. When determined on day 2, 3, or 6 at 6 P.M., i.e., at the end of the food consumption period, [14C]inulin clearance was increased in all animals compared with the value determined at 10 A.M. in the fasted state. The use of implanted osmotic minipumps for delivering a glomerular marker such as [14C]inulin allows the determination of GFR in conscious unrestrained rats with normal fluid balance conditions. This method appears to be particularly appropriate for studying the influence of the intake and composition of food on GFR in physiological conditions.

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

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.

Role of renal nerves in response to volume expansion in conscious newborn lambs

1989 ◽  
Vol 257 (6) ◽  
pp. R1519-R1525 ◽  
Author(s):  
F. G. Smith ◽  
T. Sato ◽  
O. J. McWeeny ◽  
L. Torres ◽  
J. E. Robillard
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Plasma Renin Activity ◽  
Glomerular Filtration ◽  
Atrial Natriuretic Factor ◽  
Volume Expansion ◽  
Filtration Rate ◽  
Plasma Renin ◽  
Renin Activity ◽  
Renal Nerves

The present study was designed to determine the influence of renal nerves in mediating the renal response to volume expansion in conscious newborn lambs. Bilateral renal denervation (n = 9) or sham surgery (n = 14) was carried out in newborn lambs 3 to 4 days before performing experiments. Lambs were between 6 and 12 days of age when studied. Chronic denervation did not alter basal neonatal renal function nor renal hemodynamics. Volume expansion with isotonic saline equal to 5% of body weight was associated with a fall in hematocrit and an increase in mean arterial blood pressure, glomerular filtration rate, urine flow rate, and Na+ excretion in intact and denervated lambs. In intact lambs, atrial natriuretic factor increased from 98 +/- 28 to 176 +/- 48 ng/ml during volume expansion and remained elevated for 1 h after volume expansion. In addition, plasma renin activity fell from 21 +/- 5 to 8 +/- 1 ng.ml-1.h-1 and aldosterone levels fell from 160 +/- 24 to 59 +/- 7 pg/ml by 150 min after the start of volume expansion. Similar changes in atrial natriuretic factor, plasma renin activity, and aldosterone were observed in denervated lambs. However, the increase in glomerular filtration rate, Na+ excretion, and fractional excretion of Na+ after volume expansion were significantly less in denervated than in intact lambs. Thus, in the newborn, the renal nerves do not appear to play a role in influencing basal renal hemodynamics and renal function but, as in the adult, the renal sympathetic nervous system does play a role in regulating fluid and electrolyte excretion during hypervolemia.

scholarly journals Extracellular Volume and Glomerular Filtration Rate in Children with Chronic Kidney Disease

2011 ◽  
Vol 6 (4) ◽  
pp. 741-747 ◽  
Author(s):  
Alison G. Abraham ◽  
Alvaro Muñoz ◽  
Susan L. Furth ◽  
Bradley Warady ◽  
George J. Schwartz
Keyword(s):  
Chronic Kidney Disease ◽  
Glomerular Filtration Rate ◽  
Kidney Disease ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Extracellular Volume

Glomerular filtration rate in weaned elephant seal pups during natural, long term fasts

1989 ◽  
Vol 67 (7) ◽  
pp. 1752-1756 ◽  
Author(s):  
S. D. Pernia ◽  
D. P. Costa ◽  
C. Leo Ortiz
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Water Conservation ◽  
Urine Output ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Absolute Magnitude ◽  
Elephant Seal ◽  
Tubular Reabsorption ◽  
The Difference

Low urine output (< 200 mL/day) seen in weaned elephant seal pups is consistent with the physiological necessity of strict water conservation during periods of protracted, natural fasts. However, urine output represents only the difference between glomerular filtration rate (GFR) and tubular reabsorption and thus provides no information about the absolute magnitude of these parameters or their role in homeostatic regulation during the fast. We measured GFR, and extracellular volume (ECV) and estimated tubular reabsorption in seven pups that had been fasting > 6 weeks and in three others that had begun to feed in captivity using standard [3H]inulin and [125I]iothalamate clearance techniques. In fasting pups, GFR and ECV ranged from 78.9 to 135.2 mL/min and from 6.3 to 15.4 L, respectively. The GFR values are 59–91% [Formula: see text] of that predicted by standard body mass allometry. These data suggest that (i) low urine output is a consequence of tubular reabsorption rather than depressed GFR; (ii) a small but significant N and electrolyte load resulting from oxidation and reorganization of body tissue during development requires near "normal" renal function despite the potential loss of water from excess urine formation.

A Role for Tubuloglomerular Feedback in Chronic Partial Ureteral Obstruction

Physiology ◽  
1993 ◽  
Vol 8 (2) ◽  
pp. 74-79
Author(s):  
P Morsing
Keyword(s):  
Renal Function ◽  
Arachidonic Acid ◽  
Ureteral Obstruction ◽  
Volume Expansion ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Tubuloglomerular Feedback ◽  
Arachidonic Acid Metabolites ◽  
Acid Metabolites ◽  
Extracellular Volume Expansion

Animals with partial ureteral obstruction have an inability to increase urinary output and glomerular filtration rate in response to an extracellular volume expansion. The mechanism may be a paradoxical resetting of tubuloglomerular feedback in the obstructed kidney, which impacts the roles of arachidonic acid metabolites and kinins in renal function.

Mechanism of natriuresis following intravascular and extracellular volume expansion

1969 ◽  
Vol 47 (2) ◽  
pp. 153-159 ◽  
Author(s):  
H. Sonnenberg ◽  
S. Solomon
Keyword(s):  
Blood Volume ◽  
Volume Expansion ◽  
Filtration Rate ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Sodium Reabsorption ◽  
Fluid Compartment ◽  
Proximal Tubular ◽  
Extracellular Volume Expansion ◽  
A Site

In clearance studies in rats, increases in filtration rate and electrolyte excretion were observed following both intravascular and extracellular fluid volume expansion. The inulin concentration ratio of proximal tubular fluid to plasma was decreased with extracellular expansion. Neither natriuresis nor fractional sodium reabsorption was related to the degree of intravascular expansion. Microperfusion studies demonstrated a decrease in proximal sodium reabsorption only when both intravascular and extravascular volumes were expanded; net sodium transport was not affected by a blood volume increase alone. From the data it is concluded that in the rat an increase in blood volume is followed by a rise of filtration rate and a fall of fractional reabsorption at a site distal to the proximal tubule, resulting in diuresis and natriuresis. If, in addition, the interstitial fluid compartment is expanded, a direct inhibition of the active transport component of proximal Na+ reabsorption occurs.

The effects of age, race and heredity on glomerular filtration rate following volume expansion and contraction in normal man

1980 ◽  
Vol 279 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Friedrich C. Luft ◽  
Naomi S. Fineberg ◽  
Judy Z. Miller ◽  
Laura I. Rankin ◽  
Clarence E. Grim ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Volume Expansion ◽  
Filtration Rate ◽  
Normal Man
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