scholarly journals Sequential changes in urine production, glomerular filtration rate, and electrolyte excretion after mannitol administration

2019 ◽  
Vol 33 (3) ◽  
pp. 1362-1367
Author(s):  
Gilad Segev ◽  
Cheryl Stafford ◽  
John Kirby ◽  
Larry D. Cowgill
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Electrolyte Excretion ◽  
Urine Production

Neurogenic regulation of proximal bicarbonate and chloride reabsorption

1986 ◽  
Vol 250 (1) ◽  
pp. F22-F26 ◽  
Author(s):  
M. G. Cogan
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Sprague Dawley ◽  
Electrolyte Excretion ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Single Nephron ◽  
Renal Nerve Activity ◽  
Chloride Excretion

Although a change in renal nerve activity is known to alter proximal reabsorption, it is unclear whether reabsorption of NaHCO3 or NaCl or both are affected. Sprague-Dawley rats (n = 10) were studied using free-flow micropuncture techniques during euvolemia and following acute ipsilateral denervation. Glomerular filtration rate and single nephron glomerular filtration rate were stable. Absolute proximal bicarbonate reabsorption fell following denervation (933 +/- 40 to 817 +/- 30 pmol/min) with a parallel reduction in chloride reabsorption (1,643 +/- 116 to 1,341 +/- 129 peq/min). Urinary sodium, potassium, bicarbonate, and chloride excretion all increased significantly. To further assess the physiological significance of neurogenic modulation of proximal transport, other rats (n = 6) were subjected to acute unilateral nephrectomy (AUN). There is evidence that AUN induces a contralateral natriuresis (renorenal reflex) at least partially by causing inhibition of efferent renal nerve traffic. AUN caused significant changes in proximal NaHCO3 and NaCl reabsorption as well as in whole kidney electrolyte excretion in the same pattern as had denervation. Prior denervation of the remaining kidney prevented the proximal and whole kidney response to AUN (n = 6). In conclusion, depression of renal nerve activity inhibits both NaHCO3 and NaCl reabsorption in the rat superficial proximal convoluted tubule. The data are consistent with the hypothesis that changes in renal nerve activity modify whole kidney electrolyte excretion under physiological conditions at least partially by regulating proximal transport.

scholarly journals Age and renal prostaglandin inhibition during exercise and heat stress

1999 ◽  
Vol 86 (6) ◽  
pp. 1936-1943 ◽  
Author(s):  
W. B. Farquhar ◽  
W. L. Kenney
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Acute Exercise ◽  
Free Water ◽  
Placebo Control ◽  
Free Water Clearance ◽  
Urine Production

Aging is associated with a number of physiological changes that may cause the kidney to rely to a greater extent on vasodilatory PGs for normal functioning. Acute exercise has been shown to cause renal vasoconstriction that may be partially buffered by vasodilatory PGs. To determine the relative importance of renal PGs during exercise in older adults, we compared the renal effects of the PG inhibitor ibuprofen (1.2 g/day for 3 days) vs. a placebo control in a cohort of eight younger (24 ± 2 yr) and eight older (64 ± 2 yr) women during treadmill exercise (∼57% maximal oxygen consumption) in the heat (36°C). This over-the-counter dose of ibuprofen reduced renal PG (i.e., PGE2) excretion by 47% ( P < 0.05). Acute exercise in the heat caused dramatic decreases in glomerular filtration rate, renal blood flow, and sodium excretion in both age groups. PG inhibition was associated with greater decreases in urine production and free water clearance ( P < 0.05). There were no drug-related declines in glomerular filtration rate or renal blood flow. We conclude that PG inhibition has only modest effects on renal function during exercise. Also, the lack of hemodynamic changes with PG inhibition indicates that healthy well-hydrated older women are not in a renal PG-dependent state.

Glomerular Filtration Rate and Electrolyte Handling in Response to Sodium Loading and Depletion. A Twin Study

1979 ◽  
Vol 28 (2) ◽  
pp. 149-154 ◽  
Author(s):  
C.E. Grim ◽  
Judy Z. Miller ◽  
Joe C. Christian
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Genetic Factors ◽  
Electrolyte Excretion ◽  
Urine Sodium ◽  
Sodium Loading ◽  
Normal Individuals ◽  
Sodium Handling ◽  
Sodium And Potassium

Possible genetic influences on glomerular filtration rate and electrolyte excretion were investigated in 55 (37 monozygotic, 18 dizygotic) young adult white twin pairs. Subjects were studied during a five-day hospitalization involving sodium loading and sodium depletion. No evidence of genetic variability was found in the control levels of serum or urine sodium and potassium. Following a saline infusion it was possible to detect genetic influence in electrolyte handling. Creatinine clearance, used as a measure of glomerular filtration rate, did not appear to be genetically mediated. The results indicate that genetic factors are important in sodium handling in normal individuals and that this is independent of glomerular filtration rate.

Effects of acute hypochloremia on glomerular filtration rate and electrolyte excretion in the dog

1958 ◽  
Vol 14 (11) ◽  
pp. 417-419 ◽  
Author(s):  
Ch. Toussaint ◽  
M. Telerman ◽  
P. Vereerstraeten
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Electrolyte Excretion

The Patterns of Renal Electrolyte Excretion in the Duck (Anas Platyrhynchos) Maintained on Freshwater and on Hypertonic Saline

1968 ◽  
Vol 48 (3) ◽  
pp. 487-508
Author(s):  
W. N. HOLMES ◽  
G. L. FLETCHER ◽  
D. J. STEWART
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Hypertonic Saline ◽  
Plasma Flow ◽  
Inorganic Phosphate ◽  
Filtration Rate ◽  
Renal Excretion ◽  
Renal Plasma Flow ◽  
Urine Flow ◽  
Electrolyte Excretion

1. The renal excretion of water and electrolytes was examined in starved ducks maintained on fresh water and on hypertonic saline containing 284 mM/1. NaCl and 6.0 mM/l. KCl. 2. No significant differences were observed in the urine flow, glomerular filtration rate, renal plasma flow and the excretory rates of K+, NH4+ and inorganic phosphate between these two groups of birds. 3. The excretory rates of Na+, Cl- and Ca2+ were significantly higher in saline-maintained birds than in the freshwater-maintained birds. 4. NH4+ appeared to be a major cationic component which occupied over half of the available osmotic space in the urine of both the freshwater-maintained and saline-maintained birds. 5. In saline-maintained birds the excretion of K+ and inorganic phosphate appeared to be independent of the available osmotic space in the urine whereas the excretion of Na+ and Cl- appeared to be very dependent upon this factor. 6. These observations suggest that the kidneys of the saline-maintained bird constitute the primary pathway for the excretion of K+, NH4+ and inorganic phosphate, and that with respect to the excretion of Na+ they constitute a relatively minor pathway.

Calculation of glomerular filtration rate expressed in mL/min from plasma cystatin C values in mg/L

2004 ◽  
Vol 64 (1) ◽  
pp. 25-30 ◽  
Author(s):  
A. Larsson ◽  
J. Malm ◽  
A. Grubb ◽  
L.-O. Hansson
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Cystatin C ◽  
Filtration Rate

Clinical Renal Function Testing by External Double Isotope Monitoring Technique

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Effective Renal Plasma Flow ◽  
Advantages And Disadvantages

SummaryAn accurate catheter-free technique for clinical determination simultaneouslyof glomerular filtration rate and effective renal plasma flow by means of radioisotopes has been developed. The renal function is estimated by the amount of radioisotopes necessary to maintain a constant concentration in the patient’s blood. The infusion pumps are steered by a feedback system, the pumps being automatically turned on when the radiation measured over the patient’s head falls below a certain preset level and turned off when this level is again readied. 131I-iodopyracet was used for the estimation of effective renal plasma flow and125I-iothalamate estimation of the glomerular filtration rate. These clearances were compared to the conventional bladder clearances and good correlation was found between these two clearance methods (correlation coefficients 0.97 and.90 respectively). The advantages and disadvantages of this new clearance technique are discussed.

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