Electrolyte excretion and free-water production during onset of acute diuresis

1975 ◽  
Vol 228 (5) ◽  
pp. 1304-1312 ◽  
Author(s):  
GH Mudge ◽  
WJ Cooke ◽  
WO Berndt
Keyword(s):  
Ethacrynic Acid ◽  
Collecting Duct ◽  
Chloride Concentration ◽  
Free Water ◽  
Inulin Clearance ◽  
Water Production ◽  
Electrolyte Excretion ◽  
Urinary Chloride ◽  
Transient Rise ◽  
Anesthetized Dogs

The concentration of major urinary solutes was studied in ureteral urine collected at 15- to 30-s intervals at the onset of acute diuresis induced in anesthetized dogs either by high-ceiling diuretics (mainly ethacrynic acid) or by osmotic diuretics. Phosphate/inulin clearance ratios remained unchanged; potassium/inulin clearance ratios rose rapidly. Principal attention is given to the mechanisms underlying a transient rise in urinary sodium and chloride concentrations during the onset of diuresis. When the data are corrected for washout artifacts from the pelvis and ureter, it can be shown that the initial collection periods are associated with a transient increase in free-water production and by the simultaneous secretion of urea from the interstitium into the tubular fluid. The former coincides in time with the rise in urinary chloride concentration and represents an augmentation of water reabsorbed in the collecting duct, which is relatively impermeable to chloride. Both responses are quantitatively consistent with the transition from a hyperosmotic to isosmotic medullary interstitium.

Chloride concentration gradient in newborn dogs in the presence of distal nephron blockade

1980 ◽  
Vol 239 (4) ◽  
pp. F328-F335
Author(s):  
Aviad Haramati ◽  
Leonard I. Kleinman
Keyword(s):  
Proximal Tubule ◽  
Ethacrynic Acid ◽  
Chloride Concentration ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Electrolyte Excretion ◽  
Newborn Animal ◽  
Plasma Chloride ◽  
Renal Tubular ◽  
Inner Cortex

Renal tubular Na+, Cl-, and H2O reabsorption was determined in 14 newborn dogs, 3–29 days of age, and in three adult dogs. In all animals NaCl reabsorption beyond the proximal tubule was blocked with ethacrynic acid (2 mg/kg) and amiloride (2.4 mg/kg). During distal blockade, fractional reabsorption of NaCl and water in both newborns and adults was approximately 70%, and there was a urine-to-plasma chloride gradient equal to 1.34 ± 0.01, indicating that the proximal tubules of the newborn as well as those of the adult can generate a transtubular Cl- gradient. Upon administration of acetazolamide (50 mg/kg), there was a dramatic increase in excretion of Na+, Cl-, HCO3-, and water, and a decrease in the transtubular chloride gradient. After acetazolamide, the degree of inhibition of HCO3- reabsorption was well correlated with that of Na+ (r = 0.77) or Cl- (r = 0.74), and Na+ or Cl- inhibition exceeded that of HCO3- In the newborn animal, the ratio of inner-to-outer cortical nephron function is high at birth and declines rapidly during the first few weeks of life. However, there was no correlation between age and changes in either electrolyte excretion or in the transtubular chloride gradient. Therefore, the newborn dog possesses Cl- permselective tubules in the inner cortex that, in the presence of intact HCO3- reabsorption, are capable of establishing a functional transtubular Cl- gradient contributing to NaCl reabsorption. bicarbonate reabsorption; sodium reabsorption; ethacrynic acid; amiloride; acetazolamide; proximal tubule Submitted on October 29, 1979 Accepted on April 18, 1980

DIFFERENTIAL EFFECTS OF FUROSEMIDE AND ETHACRYNIC ACID ON ELECTROLYTE EXCRETION IN ANESTHETIZED DOGS

1975 ◽  
Vol 19 (5) ◽  
pp. 433
Author(s):  
P. C. ALGUIRE ◽  
M. D. BAILIE ◽  
W. J. WEAVER ◽  
D. G. TAYLOR ◽  
J. B. HOOK
Keyword(s):  
Ethacrynic Acid ◽  
Electrolyte Excretion ◽  
Differential Effects ◽  
Anesthetized Dogs

Excretion of Salt and Water by Patients with Sickle-Cell Anaemia: Effect of a Diuretic and Solute Diuresis

1977 ◽  
Vol 53 (6) ◽  
pp. 523-527 ◽  
Author(s):  
T. E. Forrester ◽  
G. A. O. Alleyne
Keyword(s):  
Sodium Chloride ◽  
Sickle Cell ◽  
Sodium Excretion ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Sickle Cell Anaemia ◽  
Ethacrynic Acid ◽  
Free Water ◽  
Loop Of Henle ◽  
Water Reabsorption

1. Patients with sickle-cell anaemia were unable to increase free water reabsorption (TcH2O) in response to intravenous hypertonic sodium chloride solution. 2. Ethacrynic acid caused a brisk natriuresis in patients with sickle-cell anaemia but fractional sodium excretion was lower in these patients. 3. These findings could be explained by abnormal function of the loop of Henle.

THE USE AND MODE OF ACTION OF ETHACRYNIC ACID IN NEPHROGENIC DIABETES INSIPIDUS

PEDIATRICS ◽  
1966 ◽  
Vol 37 (3) ◽  
pp. 447-455
Author(s):  
David M. Brown ◽  
John W. Reynolds ◽  
Alfred F. Michael ◽  
Robert A. Ulstrom
Keyword(s):  
Renal Function ◽  
Diabetes Insipidus ◽  
Nephrogenic Diabetes Insipidus ◽  
Acid Metabolism ◽  
Ethacrynic Acid ◽  
Sodium Intake ◽  
Urine Volume ◽  
Free Water ◽  
Chloride Excretion ◽  
Diuretic Agents

The use of diuretic agents in the treatment of nephrogenic diabetes insipidus had been reported to result in decreased urine volume and decreased clearance of free water. A study of the use of ethacrynic acid, a potent saluretic agent, was instituted in patients with nephrogenic diabetes insipidus in an attempt to achieve a significant antidiuretic response while allowing a liberal sodium diet. Intravenous ethacrynic acid resulted in decreased urine volume, decreased clearance of free water and decreased RPF and GFR. Prolonged oral administration of ethacrynic acid promoted a significant antidiuretic response when the daily sodium intake was limited to 60 mEq. The effect of ethacrynic acid on renal function, potassium and chloride. excretion, and uric acid metabolism are discussed.

Acute effects of lithium on the renal concentrating mechanism in a primate

1975 ◽  
Vol 228 (3) ◽  
pp. 909-914 ◽  
Author(s):  
RK Webb ◽  
PB Woodhall ◽  
CC Tisher ◽  
RR Robinson
Keyword(s):  
Spontaneous Recovery ◽  
Collecting Duct ◽  
Free Water ◽  
Acute Effects ◽  
Water Reabsorption ◽  
Short Term ◽  
Free Water Clearance ◽  
Concentrating Mechanism ◽  
Renal Concentrating Mechanism ◽  
Acute Lithium

Although chronic lithium therapy has been associated with a defect in the urinary concentrating mechanism, short-term renal effects of lithium have received little attention in the intact animal. Solute-free water reabsorption (T-cH2O) and free water clearance (CH2O) were measured in primates of the genus Galago under control conditions and while animals were receiving either 0.5 mmol/kg-h or 1.0 mmol/kg-h lithium chloride (135 mM) intravenously. CH2O was unchanged by lithium infusion (P greater than 0.10), whereas T-cH2O was significantly depressed at all levels of osmolal clearance (P smaller than 0.01). Spontaneous recovery of near-normal T-cH2O was documented in two animals within 1 wk following acute lithium infusion. In addition it was observed that lithium-induced depression of T-cH2O could be partially prevented by pretreatment with intravenous amiloride. These results suggest that alterations in the renal concentrating mechanism can occur rapidly following the onset of lithium administration. They also imply that impairment of the renal concentrating mechanism by lithium is due at least in part to antagonism of the action of vasopressin on the collecting duct.

Regional and segmental localization of AE2 anion exchanger mRNA and protein in rat kidney

1995 ◽  
Vol 269 (4) ◽  
pp. F461-F468 ◽  
Author(s):  
F. C. Brosius ◽  
K. Nguyen ◽  
A. K. Stuart-Tilley ◽  
C. Haller ◽  
J. P. Briggs ◽  
...  
Keyword(s):  
Collecting Duct ◽  
Rat Kidney ◽  
Chloride Concentration ◽  
Transepithelial Transport ◽  
Thick Ascending Limb ◽  
Cortical Collecting Duct ◽  
Base Exchange ◽  
Medullary Thick Ascending Limb ◽  
Nephron Segment ◽  
Medullary Collecting Duct

Chloride/base exchange activity has been detected in every mammalian nephron segment in which it has been sought. However, in contrast to the Cl-/HCO3- exchanger AE1 in type A intercalated cells, localization of AE2 within the kidney has not been reported. We therefore studied AE2 expression in rat kidney. AE2 mRNA was present in cortex, outer medulla, and inner medulla. Semiquantitative polymerase chain reaction of cDNA from microdissected tubules revealed AE2 cDNA levels as follows [copies of cDNA derived per mm tubule (+/- SE)]: proximal convoluted tubule, 688 +/- 161; proximal straight tubule, 652 +/- 189; medullary thick ascending limb, 1,378 +/- 226; cortical thick ascending limb, 741 +/- 24; cortical collecting duct, 909 +/- 71; and outer medullary collecting duct, 579 +/- 132. AE2 cDNA was also amplified in thin limbs and in inner medullary collecting duct. AE2 polypeptide was detected in all kidney regions. AE2 mRNA and protein were also detected in several renal cell lines. The data are compatible with the postulated roles of AE2 in maintenance of intracellular pH and chloride concentration and with its possible participation in transepithelial transport.

scholarly journals Reduced AQP1, -2, and -3 levels in kidneys of rats with CRF induced by surgical reduction in renal mass

1998 ◽  
Vol 275 (5) ◽  
pp. F724-F741 ◽  
Author(s):  
Tae-Hwan Kwon ◽  
Jørgen Frøkiaer ◽  
Mark A. Knepper ◽  
Søren Nielsen
Keyword(s):  
Urine Output ◽  
Renal Mass ◽  
Collecting Duct ◽  
Free Water ◽  
Urine Osmolality ◽  
Urinary Concentration ◽  
Water Reabsorption ◽  
Similar Reduction ◽  
Urine Production ◽  
Quantitative Immunoblotting

Urinary concentration characteristically decreases in response to a reduction in renal mass in chronic renal failure (CRF). In the present study, we examined whether there are changes in the expression of aquaporins in rats where CRF was induced by 5/6 nephrectomy. Plasma creatinine levels were significantly elevated consistent with significant CRF: 135.7 ± 15.1 ( n = 17, CRF) vs. 33.9 ± 1.1 μmol/l ( n = 11, sham), P < 0.05. Two weeks after 5/6 nephrectomy, the remnant kidneys were hypertrophied, and total renal mass increased to 65 ± 3% of sham levels ( P < 0.05). Urine production increased markedly from 40 ± 2 to 111 ± 3 μl ⋅ min−1 ⋅ kg−1in CRF rats ( P < 0.05), whereas urine osmolality and solute-free water reabsorption decreased significantly. Quantitative immunoblotting of total kidney membrane fractions revealed a significant decrease in total kidney AQP2 expression in CRF rats to 43 ± 12% of sham levels ( P < 0.05). A similar reduction was observed for AQP1 and AQP3. Furthermore, the increased urine output and decreased urine osmolality persisted in CRF rats despite 7 days treatment with 1-desamino-[8-d-arginine]vasopressin (DDAVP, 0.1 μg/h sc) compared with untreated sham-operated controls. Also, there was no change in AQP2 expression (which remained at 38 ± 3% of sham levels, P < 0.05), urine output, or urine osmolality between CRF rats with or without DDAVP treatment. Immunocytochemistry confirmed the decreased AQP2 expression in collecting duct principal cells in CRF rats, with a predominant apical labeling. In conclusion, the results demonstrated that there was a significant vasopressin-resistant downregulation of AQP2 and AQP3 as well as downregulation of AQP1 associated with the polyuria in CRF rats.

Effect of calcitonin on urine concentration in the rat

1983 ◽  
Vol 244 (4) ◽  
pp. F432-F435 ◽  
Author(s):  
S. Carney ◽  
T. Morgan ◽  
C. Ray ◽  
L. Thompson
Keyword(s):  
Water Permeability ◽  
Partial Agonist ◽  
Collecting Duct ◽  
Free Water ◽  
Urine Concentration ◽  
Distal Nephron ◽  
Free Water Clearance ◽  
Normal Increase

Because mammalian distal nephron segments with both calcitonin- and antidiuretic hormone- (ADH) sensitive adenylate cyclase activity have been described, in vivo and in vitro experiments were performed to study the effect of calcitonin on rat distal nephron water permeability. Calcitonin 1 and 0.1 U/ml, but not 0.01 U/ml, significantly increased the diffusional water permeability in the isolated papillary collecting duct by 15 and 11%, respectively. However, this effect was small when compared with a 68% increase with a supramaximal concentration of ADH (from 4.0 +/- 0.3 to 6.7 +/- 0.9 microns/s; n = 6, P less than 0.01). The normal increase in water permeability with increasing concentration of ADH (0.02 and 0.2 mU/ml) was depressed by the previous addition of calcitonin (1 U/ml) to the bath but was unaltered with the supramaximal ADH concentration (2 mU/ml). Verapamil, a compound that antagonizes cellular calcium entry, did not alter the effect of calcitonin on diffusional water permeability. Calcitonin in concentrations of 0.05, 0.5, and 5 U/ml produced a significant reduction in urine flow and free water clearance. Pretreatment with calcitonin in these concentrations inhibited the antidiuretic action of ADH. These studies suggest that calcitonin acts as a partial agonist to ADH within the distal nephron. It is unclear whether such an action represents a physiological or a pharmacological effect.

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