Natriuresis in Rats Acutely Depleted of Chloride

1977 ◽  
Vol 52 (1) ◽  
pp. 23-31
Author(s):  
R. G. Luke ◽  
B. T. Khanh ◽  
R. D. Schmidt ◽  
J. H. Galla
Keyword(s):  
Sodium Bicarbonate Solution ◽  
Free Water ◽  
Sodium Reabsorption ◽  
Urinary Flow ◽  
Variable Degree ◽  
Water Reabsorption ◽  
Chloride Depletion ◽  
Sodium Load ◽  
Clearance Studies ◽  
And Control

1. Acute chloride depletion, without sodium depletion, was produced in rats by a single exchange peritoneal dialysis against sodium bicarbonate solution. Blood volume was restored after dialysis by infusion of salt-free albumin, and exogenous deoxycorticosterone and antidiuretic hormone were given. 2. Clearance studies in the period (3 h) after dialysis revealed no difference in the glomerular filtration rate or in the filtered sodium load between experimental and control rats but urinary sodium concentrations and absolute and fractional sodium excretion were significantly higher in the chloride-depleted group. 3. There was also a significant kaliuresis, increased urinary flow rate and diminished free water reabsorption. Urinary bicarbonate excretion increased to a variable degree but the major rise in anion excretion was ‘unmeasured’ (Na+ + K+ — [Cl− +HCO3− +PO43-]). 4. It is postulated that chloride depletion imposes limitations on sodium reabsorption in the ascending limb of the loop of Henle.

Effect of Inhibition of Prostaglandin Synthesis on the Natriuresis Induced by Saline Infusion in Man

1978 ◽  
Vol 54 (1) ◽  
pp. 47-50 ◽  
Author(s):  
Th. Mountokalakis ◽  
Th. Karambasis ◽  
D. Mayopoulousymvoulidou ◽  
G. Merikas
Keyword(s):  
Free Water ◽  
Prostaglandin Synthesis ◽  
Saline Infusion ◽  
Sodium Reabsorption ◽  
Distal Nephron ◽  
Prostaglandin Synthetase ◽  
Water Reabsorption ◽  
Post Infusion ◽  
Inhibition Of Prostaglandin Synthesis ◽  
Natriuretic Effect

1. The effect of oral administration of an inhibitor of prostaglandin synthetase, indomethacin, on the natriuresis induced by the infusion of sodium chloride (saline) was studied in 11 healthy volunteers. 2. The administration of indomethacin did not alter sodium excretion before saline infusion, but it resulted in a significant increase of the natriuresis after saline infusion. This increase was not accompanied by any change in post-infusion urine flow rate or free water reabsorption. 3. It is suggested that intrarenal prostaglandins might suppress the natriuretic effect of saline infusion, probably by increasing sodium reabsorption in the distal nephron.

Effect of Brief Hypercalcaemia on Free Water Reabsorption during Solute Diuresis: Evidence for Impairment of Sodium Transport in Henle's Loop

1970 ◽  
Vol 39 (3) ◽  
pp. 337-347 ◽  
Author(s):  
J-P. Guignard ◽  
N. F. Jones ◽  
M. A. Barraclough
Keyword(s):  
Membrane Permeability ◽  
Hypertonic Saline ◽  
Sodium Transport ◽  
Free Water ◽  
Water Reabsorption ◽  
Henle's Loop ◽  
Sodium Load ◽  
The Relationship

1. The relationship between osmolal clearance (Cosm) and the reabsorption of solute free water (Tch2o) was examined during mannitol and hypertonic saline diureses in both normocalcaemic and hypercalcaemic rabbits. 2. At high values for Cosm (2–4 ml/min) in normocalcaemic rabbits Tch2o during saline diuresis exceeded that during mannitol diuresis as previously shown. 3. Prolonged hypercalcaemia (72–96 h) reduced Tch2o in both mannitol and saline diureses. 4. Brief hypercalcaemia (18–24 h) abolished the increment in Tch2o normally seen during saline, as compared with mannitol diuresis. This impairment of Tch2o during saline diuresis occurred at a time after the start of hypercalcaemia when Tch2o during mannitol diuresis was still unaffected. 5. The results cannot be attributed to an effect of hypercalcaemia on membrane permeability to water, and are best explained by a reversible limitation of sodium transport in Henle's loop. This interpretation is supported by the fact that the hypercalcaemic rabbits excreted a greater percentage of the filtered sodium load than did the controls.

Actions of vasotocin and some of its analogues on salt and water excretion by the frog

1963 ◽  
Vol 204 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Serge Jard ◽  
Francois Morel
Keyword(s):  
Free Water ◽  
Rana Esculenta ◽  
The Other ◽  
Sodium Reabsorption ◽  
Water Reabsorption ◽  
Water Excretion ◽  
Lysine Vasopressin ◽  
Target Organs ◽  
Small Doses ◽  
Stimulation Of

The actions of small doses of arginine and lysine-vasotocin on urine flow (V), inulin (CIn), free water (CHH2O), sodium (CNa), and potassium (CK) clearances were studied in Rana esculenta and compared with those of larger doses of oxytocin, lysine-vasopressin, Val3-oxytocin, Ileu8-oxytocin, Phe2-Phe3-Lys8-oxytocin, deamino-oxytocin, and oxypressin. Injections of either arginine or lysine-vasotocin (mean dose .030 µg) induce a small decrease in glomerular filtration rate (GFR) and two marked tubular effects: a) an increase in water reabsorption, CHH2O being reduced even when related to CIn; b) an increase in tubular sodium reabsorption, CNa/CIn being lowered, whereas CK/CIn remains unchanged. Neither oxytocin nor lysine-vasopressin, even in doses 20–25 times higher, promotes the tubular effects typical of vasotocin. Oxytocin promotes a slight decrease in GFR and V. Lysine-vasopressin remains without any effect. All the other artificial analogues of oxytocin injected in large doses increase V, GFR, CNa/CIn and CK/CIn. It is concluded that the vasotocins specifically promote in the kidney tubules of the frog the same two actions described in the other target organs in the amphibians, namely an increase in osmotic permeability to water and a stimulation of active sodium transport.

Renal Vasodilatation: Studies on the Site of Action in the Nephron

1972 ◽  
Vol 42 (5) ◽  
pp. 535-543 ◽  
Author(s):  
S. G. Massry ◽  
J. J. Ahumada
Keyword(s):  
Urine Volume ◽  
Free Water ◽  
Urinary Sodium Excretion ◽  
Sodium Reabsorption ◽  
Water Reabsorption ◽  
Diluting Segment ◽  
Free Water Clearance ◽  
Medullary Blood Flow ◽  
Site Of Action ◽  
Additional Role

1. The effect of unilateral renal vasodilatation produced by acetylcholine or bradykinin on free water clearance (CH2O) and free water reabsorption (TcH2O) was investigated in dogs in an effort to localize the site(s) in the nephron where renal vasodilatation inhibits tubular sodium reabsorption. 2. Renal vasodilatation in dogs undergoing water diuresis produced an increase in urinary sodium excretion, urine volume and CH2O. However, for any given level of sodium delivery to the diluting segment of the nephron, CH2O was less during the intrarenal infusion of the vasodilator drugs than during the infusion of hypo-osmotic saline. 3. During renal vasodilatation in hydropenic dogs receiving vasopressin and hyperosmotic saline, TcH2O at a given rate of osmolal clearance was depressed. The effect of bradykinin on TcH2O was greater than that of acetylcholine. 4. The results indicate that renal vasodilatation inhibits sodium reabsorption in the proximal tubule and the diluting segment of the nephron as well. Increased medullary blood flow may play an additional role in the effect of acetylcholine and bradykinin on TcH2O.

Stimulation of renal sodium reabsorption by angiotensin II

1977 ◽  
Vol 232 (4) ◽  
pp. F298-F306 ◽  
Author(s):  
M. D. Johnson ◽  
R. L. Malvin
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Flow Rate ◽  
Sodium Reabsorption ◽  
Urinary Flow ◽  
Filtration Fraction ◽  
Water Diuresis ◽  
Urinary Osmolality ◽  
Anesthetized Dogs ◽  
Renal Sodium Reabsorption

Various parameters of renal function were studied before, during, and after the infusion of physiological increments of angiotensin II directly into one renal artery of anesthetized dogs. During water diuresis and during antidiuresis induced with exogenous antidiuretic hormone (ADH), angiotensin II consistently reduced UNaV, UKV, and CPAH, and increased the filtration fraction in the infused kidney. Urinary osmolality was increased only in the presence of ADH, while during water diuresis angiotensin II had no apparent effect on urinary osmolality or flow rate. During saline diuresis, a mean increment of angiotensin II concentration of 14 pg/ml was sufficient to significantly reduce UNaV and urinary flow rate. Changes in CCr, CPAH, and filtration fraction did not correlate with changes in sodium excretion, and intracortical distribution of blood flow remained unaltered. These data support the hypothesis that normal circulating levels of angiogensin II play a direct renal role in the control of sodium, potassium, and water homeostasis, and that angiotensin II exerts a direct, stimulatory effect on tubular sodium reabsorption independent of changes in GFR, RPF, filtration fraction, or intracortical distribution of blood flow.

scholarly journals PECULIARITIES OF IONOREGULATORY RENAL FUNCTION OF RATS IN THE DYNAMICS OF EXPERIMENTAL DIABETES MELLITUS DEVELOPMENT WITH UNDERLYING PHARMACOLOGICAL BLOCADE OF RENIN-ANGIOTENSINALDOSTERONE SYSTEM

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
О.А. Olenovych
Keyword(s):  
Diabetes Mellitus ◽  
Renal Function ◽  
Free Water ◽  
Distal Segment ◽  
Male Rats ◽  
Sodium Reabsorption ◽  
Free Water Clearance ◽  
Glomerular Filtrate ◽  
Pharmacological Blockade

The aim of the study – to explore the role of the renin-angiotensin-aldosteronesystem (RAAS) in the disturbance of ionoregulatory renal function in alloxan-inducedexperimental diabetes mellitus (EDM).Material and methods. The experiments were carried out on 78 white non-linearmature male rats with 11-, 26- and 46-day long alloxan-induced EDM with underlyingpharmacological blockade of RAAS by administration of kaptopril. The study ofionoregulating function of the kidneys was provided by the clearance method under thecondition of water 2-hour diuresis.Results. Pharmacological blockade of RAAS in rats with alloxan-induced EDM causedan intensification of natriuresis at all stages of the experiment: increased urinaryconcentration of sodium ions, its excretion and clearance. On the 11th day of EDM, thesodium filtration charge increased with the development of hyponatremia, proximal anddistal sodium reabsorption standardized in volume of glomerular filtrate (GF) decreased,kaliuresis was suppressed, and sodium-free water clearance elevated. In case of 26-daylong EDM, the sodium filtration charge decreased, its absolute and relative reabsorption,the distal sodium reabsorption standardized by GF increased. Kaliuresis increased. In46-day long EDM, the sodium filtration charge decreased, and hyponatremia enhanced.Absolute and relative sodium reabsorption reduced due to both – proximal and distal.Kaliuresis augmented, the clearance of sodium-free water declined.Conclusions. The increase in urinary sodium loss during the 11-day EDM is stipulatedby glomerular hyperfiltration, causing a functional weakening of the tubulotubularbalance and relative dysfunction of the distal segment of the nephron, emphasizing therenoprotective effect of RAAS on ionoregulatory function of the kidneys. The decrease inthe total reabsorption potential of the tubular segment of the nephron in the dynamics ofEDM development reflects on the proximal tubules, and preserved tubulotubular balancecertifies functional intactness of the distal tubules in 26-day long EDM. RAAS pathologicalactivation and attenuation of the renal blood flow autoregulation by tubuloglomerularfeedback may serve as an initiating factor in the development of tubular disorders in 26-day long alloxan diabetes with following progression in 46-day long EDM.

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.

Mechanisms of angiotensin II natriuresis and antinatriuresis

1985 ◽  
Vol 249 (2) ◽  
pp. F299-F307 ◽  
Author(s):  
M. E. Olsen ◽  
J. E. Hall ◽  
J. P. Montani ◽  
A. C. Guyton ◽  
H. G. Langford ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Sodium Excretion ◽  
Distal Tubule ◽  
Urinary Sodium Excretion ◽  
Sodium Reabsorption ◽  
Ang Ii ◽  
Sodium Load ◽  
Proximal Tubular ◽  
Anesthetized Dogs

The aim of this study was to determine the role of changes in renal arterial pressure (RAP), renal hemodynamics, and tubular reabsorption in mediating the natriuretic and antinatriuretic actions of angiotensin II (ANG II). In seven anesthetized dogs, endogenous ANG II formation was blocked with captopril, and ANG II was infused intravenously at rates of 5-1,215 ng X kg-1 X min-1 while RAP was either servo-controlled at the preinfusion level or permitted to increase. When RAP was servo-controlled, ANG II infusion at all rates from 5-1,215 ng X kg-1 X min-1 decreased urinary sodium excretion (UNaV) and fractional sodium excretion (FENa) while increasing fractional reabsorption of lithium (FRLi) (an index of proximal tubular fractional sodium reabsorption) and causing no change in calculated distal tubule fractional sodium reabsorption (FRDNa). When RAP was permitted to increase, ANG II infusion rates up to 45 ng X kg-1. min-1 also decreased UNaV and FENa while increasing FRLi and causing no change in FRDNa. However, at 135 ng X kg-1 X min-1 and above, UNaV and FENa increased while FRLi and FRDNa decreased when RAP was allowed to rise, even though renal blood flow and filtration fraction were not substantially different from the values observed when RAP was servo-controlled. Filtered sodium load was slightly higher when RAP was permitted to increase during ANG II infusion compared with when RAP was servo-controlled, although the differences were not statistically significant. Thus, even very large doses of ANG II cause antinatriuresis when RAP is prevented from increasing.(ABSTRACT TRUNCATED AT 250 WORDS)

Stop-flow analysis applied to the excretion of hemoglobin

1960 ◽  
Vol 199 (2) ◽  
pp. 292-294 ◽  
Author(s):  
C. L. Malmendier ◽  
J. P. DeKoster ◽  
F. Vander Veiken ◽  
H. Brauman ◽  
M. DeMyttenaere ◽  
...  
Keyword(s):  
Flow Analysis ◽  
Middle Part ◽  
The Other ◽  
Physiological Data ◽  
Sodium Reabsorption ◽  
Water Reabsorption ◽  
Tubular Lumen ◽  
Influence Of Water ◽  
Stop Flow ◽  
Ureteral Occlusion

The stop-flow analysis has been applied to the study of the excretion of hemoglobin, in order to compare the physiological data with the morphological views. The study of the ratio U/P hemoglobin/U/P creatinine suggests that this protein penetrates the tubular lumen by diffusion during the ureteral occlusion and progressed slowly under influence of water reabsorption. During this migration, hemoglobin undergoes the effects of a double reabsorption: one in the middle part of the proximal convoluted tubule, the other more distally situated in a zone not distinguishable from the site of sodium reabsorption.

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