Renal acid-base physiology in marine teleost, the long-horned sculpin (Myoxocephalus octodecimspinosus)

We have sought to define urinary acid-base excretion in the marine teleost using the long-horned sculpin, Myoxocephalus octodecimspinosus. Urine flow (1.7 ml.h-1.kg-1) is relatively high, and glomerular filtration rate is very low (2.9 ml.h-1.kg-1). The urine-to-plasma ratio of inulin is 2. Renal clearance of p-aminohippurate is very high (108 ml.h-1.kg-1); phosphate and divalent cations are also secreted. In this framework we found urinary pH to average 6.6, but infusion of acid or alkali elicited a pH range of 6.1-7.8. Untreated fish may also have alkaline urine; so it is not surprising that precipitates of calcium or magnesium phosphate are sometimes found in bladder. These are of fine sandy quality and never cause blockage. Infusion of buffer (imidazole) increased the concentration of titratable acid 11-fold and output 2.5-fold. Carbonic anhydrase inhibitors had no effect on any urinary component, and histochemical studies revealed that cytoplasm and membranes did not yield the specific cobalt stain for the enzyme. An alkaline load (NaHCO3) is rapidly dissipated by gill excretion, mediated in part by carbonic anhydrase. An acid load (HCl) is rapidly dissipated by gill excretion, not dependent on carbonic anhydrase, and some renal excretion. Comparison and contrast of the low rates of HCO3- reabsorption in the marine teleost (and elasmobranch) with those of mammals suggest strongly that renal carbonic anhydrase evolved in connection with these high reabsorptive rates beginning in freshwater fish and continuing through amphibia and birds.

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Renal regulation of acid-base balance in the bullfrog

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1961.201.6.980 ◽

1961 ◽

Vol 201 (6) ◽

pp. 980-986 ◽

Cited By ~ 15

Author(s):

Hisato Yoshimura ◽

Masateru Yata ◽

Minoru Yuasa ◽

Robert A. Wolbach

Keyword(s):

Carbonic Anhydrase ◽

Ammonia Excretion ◽

Respiratory Acidosis ◽

Acid Base Balance ◽

Acid Base ◽

Urinary Ph ◽

Base Balance ◽

Chloride Excretion ◽

Acid Load ◽

Renal Carbonic Anhydrase

Renal mechanisms for the maintenance of acid-base balance were studied in the normal bullfrog, during metabolic and respiratory acidosis, and after carbonic anhydrase inhibition. Following intravenous administration of 0.3–12 mmole HCl/ kg, as 0.1 n HCl, urinary pH (initially pH 6.3–7.7) did not change significantly. However, urinary ammonia excretion increased more than twofold, and within 3–5 days the cumulative increase was equivalent to the acid load given. Despite the increased ammonia excretion, chloride excretion did not increase after acid loading. In both normal and acidotic bullfrogs ammonia excretion was correlated with an increase in urinary pH. Respiratory acidosis in the small frog, Rana limnocharis, produced by exposure to 6.4% CO2 in air, induced neither urinary acidification nor increased ammonia excretion; both urinary sodium and bicarbonate excretion increased. When renal carbonic anhydrase was inhibited by acetazoleamide injection, urine flow, sodium excretion, and bicarbonate excretion increased markedly, urinary pH increased slightly, and urinary ammonia excretion remained unchanged. These renal responses to acidosis are compared with those of the acidotic dog.

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Effects of Prolonged Administration of Diamox on Excretion of Acid and Carbonic Anhydrase and Glutaminase Activities in the Kidney

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1957.189.3.551 ◽

1957 ◽

Vol 189 (3) ◽

pp. 551-556 ◽

Cited By ~ 9

Author(s):

Donald W. Seldin ◽

Floyd C. Rector ◽

H. C. Teng

Keyword(s):

Carbonic Anhydrase ◽

Enzyme System ◽

Chronic Administration ◽

Carbonic Anhydrase Activity ◽

Prolonged Administration ◽

Urine Ph ◽

Alkaline Urine ◽

Titratable Acid ◽

Load Effects ◽

Renal Carbonic Anhydrase

Diamox inhibits renal carbonic anhydrase activity as effectively when given chronically as when given acutely. The persistently high urine ph, low titratable acid and high bicarbonate excretion in the urine of rats receiving Diamox chronically were the result of the alkaline load effects of sodium Diamox, rather than effects from the inhibition of carbonic anhydrase. The chronic administration of Diamox activated the renal glutaminase enzyme system, resulting in the excretion of normal or increased amounts of ammonia into an alkaline urine. The activation of glutaminase was potentiated by the restriction of dietary NaCl. An unexplained hypernatremia developed during the course of prolonged administration of Diamox.

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Effect of Diamox on plasma and urine acid-base composition during chronic respiratory acidosis

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1959.196.4.919 ◽

1959 ◽

Vol 196 (4) ◽

pp. 919-923 ◽

Cited By ~ 11

Author(s):

Norman W. Carter ◽

Donald W. Seldin ◽

H. C. Teng

Keyword(s):

Carbonic Anhydrase ◽

Carbonic Acid ◽

Ammonia Excretion ◽

Respiratory Acidosis ◽

High Plasma ◽

Renal Tubular Cell ◽

The Face ◽

Renal Carbonic Anhydrase ◽

Renal Tubular ◽

Very High

Diamox, administered during experimental chronic respiratory acidosis in an amount sufficient to inhibit completely renal carbonic anhydrase, resulted in marked increase in plasma pCO2 and bicarbonate concentration. Inhibition of red blood cell carbonic anhydrase was probably responsible for the very high plasma pCO2 observed. The high pCO2, in turn, was capable of so accelerating the uncatalyzed formation of carbonic acid in the renal tubular cell that sufficient secretion of hydrogen ion occurred to accomplish reabsorption of even increased amounts of filtered bicarbonate in the face of complete inhibition of renal carbonic anhydrase. Despite accelerated bicarbonate reabsorption, hyperchloremia and potassium deficiency supervened in blood, ammonia excretion increased, and renal glutaminase was activated.

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Inorganic carbon acquisition by Chlamydomonas acidophila across a pH range

Canadian Journal of Botany ◽

10.1139/b05-073 ◽

2005 ◽

Vol 83 (7) ◽

pp. 872-878 ◽

Cited By ~ 23

Author(s):

Elly Spijkerman

Keyword(s):

Growth Rate ◽

Carbonic Anhydrase ◽

Inorganic Carbon ◽

Maximum Growth ◽

Maximum Growth Rate ◽

Chlamydomonas Acidophila ◽

Ph Conditions ◽

Ph Range ◽

Very High ◽

External Ph

Chlamydomonas acidophila Negoro had a higher maximum growth rate upon aeration with 5% CO2 (v/v) than in nonaerated conditions at an external pH above 2. In medium with a pH of 1.0 or 2.0, a decrease in the maximum growth rate was observed upon CO2 aeration in comparison with nonaerated conditions. At both very low and very high external pH conditions, an induction of external carbonic anhydrase was detected; this being more pronounced in CO2-aerated cells than in nonaerated cells. It is therefore suggested that the induction of carbonic anhydrase is part of a stress response in Chlamydomonas acidophila. Comparison of some physiological characteristics of Chlamydomonas acidophila acclimated at pH 2.65 and at pH 6.0, revealed that CO2 aeration increased gross maximum photosynthesis at both pHs, whereas respiration, light acclimation, and photoinhibition were not effected. At pH 2.65, Chlamydomonas acidophila was found to have a carbon-concentrating mechanism under nonaerated conditions, whereas it did not under CO2-aerated conditions at pH 6. The affinity for CO2 use in O2 production was not dependent on CO2 aeration, but it was much lower at pH 6 than it was at pH 2.65. CO2 kinetic characteristics indicate that the photosynthesis of Chlamydomonas acidophila in its natural environment is not limited by inorganic carbon.Key words: Chlamydomonas acidophila, CCM, external carbonic anhydrase, photosynthesis, growth rates, pH stress, CO2.

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The effects of the inhibition of the renal carbonic anhydrase on the blood acid-base status in hypercapnic rats

Comparative Biochemistry and Physiology Part A Physiology ◽

10.1016/0300-9629(85)90277-4 ◽

1985 ◽

Vol 81 (1) ◽

pp. 121-126

Author(s):

A Bar-Ilan ◽

J Marder

Keyword(s):

Carbonic Anhydrase ◽

Acid Base ◽

Renal Carbonic Anhydrase ◽

Acid Base Status

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Grand-Reaction Method for Simulations of Ionization Equilibria and Ion Partitioning in a Broad Range of pH and Ionic Strength

10.26434/chemrxiv.9741746.v1 ◽

2019 ◽

Author(s):

Jonas Landsgesell ◽

Oleg Rud ◽

Pascal Hebbeker ◽

Raju Lunkad ◽

Peter Košovan ◽

...

Keyword(s):

Mean Field ◽

Coarse Grained ◽

Reactive System ◽

Acid Base ◽

Buffer Solution ◽

Reaction Method ◽

Ionization Equilibria ◽

Coarse Grained Simulations ◽

Ph Range ◽

Weak Polyelectrolytes

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>

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RENAL CARBONIC ANHYDRASE IN PREMATURE AND MATURE INFANTS

PEDIATRICS ◽

10.1542/peds.7.2.182 ◽

1951 ◽

Vol 7 (2) ◽

pp. 182-185

Author(s):

RICHARD DAY ◽

JANE FRANKLIN

Keyword(s):

Carbonic Anhydrase ◽

Premature Infants ◽

Carbonic Anhydrase Activity ◽

Renal Carbonic Anhydrase

The carbonic anhydrase activity in the kidneys of premature infants was studied because it was thought that if the renal enzyme is as deficient as that in the blood, inefficiency in acidification of urine might result. In contrast with the blood, postmortem specimens of kidneys of premature infants were found to exhibit carbonic anhydrase activity similar to that found in the case of kidneys from older infants and adults.

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Phosphate removal in real anaerobic supernatants: modelling and performance of a fluidized bed reactor

Water Science & Technology ◽

10.2166/wst.1998.0065 ◽

1998 ◽

Vol 38 (1) ◽

pp. 275-283 ◽

Cited By ~ 21

Author(s):

P. Battistoni ◽

P. Pavan ◽

F. Cecchi ◽

J. Mata-Alvarez

Keyword(s):

Fluidized Bed ◽

Contact Time ◽

Fluidized Bed Reactor ◽

Phosphate Removal ◽

Plant Design ◽

Air Stripping ◽

And Performance ◽

Ph Range ◽

Very High ◽

A2o Process

Phosphate removal in anaerobic supernatant coming from a centrifugation sludge station of an A2O process is studied. A fluidized bed reactor is employed to crystallize phosphate as hydroxyapatite or struvite using only air stripping to reach the supersaturation pH. The classic composition of supernatant (alkalinity 3550 mgCaCO3/l, PO4 139 mg/l, Mg 24 mg/l) does not require any addition of chemicals for phosphate removal. Seventeen runs are performed in a bench scale FBR obtaining very high conversion and removal efficiency and phosphate loss in the effluent ≤3.5%. The use of Ca or Mg enriched supernatant has no meaningful influence on efficiency, but it determines the prevalent salt formed between MAP or HAP. Efficiency can be related to pH and sand contact time in a double saturational model. The half efficiency constants: 0.075 h for t and 7.75 pH, have an important role in the process knowledge and optimization of plant design. Exhaust sand analysis indicates the same composition at the top, bottom and mean of the sand bed (39% mol MAP and 61% mol HAP). This result together with the high half efficiency constant for contact time indicate that the phosphate growth on the bed is not competitive. Finally, the phosphate release from the plant is studied. Results show a weak release rate, equivalent to 2.8-10% d−1 phosphate as MAP, obtained at an operative pH range of 8.1-8.4.

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A mathematical model of rat collecting duct II. Effect of buffer delivery on urinary acidification

AJP Renal Physiology ◽

10.1152/ajprenal.00163.2002 ◽

2002 ◽

Vol 283 (6) ◽

pp. F1252-F1266 ◽

Cited By ~ 7

Author(s):

Alan M. Weinstein

Keyword(s):

Mathematical Model ◽

Carbonic Anhydrase ◽

Collecting Duct ◽

Phosphate Concentration ◽

Rate Coefficients ◽

Urinary Flow ◽

Urinary Acidification ◽

Model Predictions ◽

Disequilibrium Ph ◽

Urinary Acid

A mathematical model of the rat collecting duct (CD) is used to examine the effect of delivered load of bicarbonate and nonbicarbonate buffer on urinary acidification. Increasing the delivered load of HCO[Formula: see text] produces bicarbonaturia, and, with luminal carbonic anhydrase absent, induces a disequilibrium luminal pH and a postequilibration increase in urinary Pco 2. At baseline flows, this disequilibrium disappears when luminal carbonic anhydrase rate coefficients reach 1% of full catalysis. The magnitude of the equilibration Pco 2 depends on the product of urinary acid phosphate concentration and the disequilibrium pH. Thus, although increasing phosphate delivery to the CD decreases the disequilibrium pH, the increase in urinary phosphate concentration yields an overall increase in postequilibration Pco 2. In simulations of experimental HCO[Formula: see text] loading in the rat, model predictions of urinary Pco 2 exceed the measured Pco 2 of bladder urine. In part, the higher model predictions for urinary Pco 2 may reflect higher urinary flow rates and lower urinary phosphate concentrations in the experimental preparations. However, when simulation of CD function during HCO[Formula: see text] loading acknowledges the high ambient renal medullary Pco 2 (5), the predicted urinary Pco 2 of the model CD is yet that much greater. This discrepancy cannot be resolved within the model but requires additional experimental data, namely, concomitant determination of urinary buffer concentrations within the tubule fluid sampled for Pco 2 and pH. This model should provide a means for simulating formal testing of urinary acidification and thus for examining hypotheses regarding transport defects underlying distal renal tubular acidosis.

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