Coupling of Transmural Flows of NaCl and Water in the Intestine of the EEl (Anguilla Anguilla)

1974 ◽  
Vol 60 (2) ◽  
pp. 535-546 ◽  
Author(s):  
ERIK SKADHAUGE
Keyword(s):  
Water Flow ◽  
Permeability Coefficient ◽  
Sea Water ◽  
Water Movement ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Surrounding Water ◽  
Pronounced Increase ◽  
Osmotic Permeability ◽  
Local Osmosis

1. An in vivo perfusion of the intestine of the yellow European eel (Anguilla anguilla) was used to measure the net absorption of NaCl and water, the osmotic permeability coefficient, the solute-linked water flow, and the osmolality difference against which the intestine could transport water as functions of the salinity of the surrounding water. The eels were adapted to fresh water, to sea water, and to 1½ strength sea water. 2. The osmolality difference against which the intestine could transport water was observed to be linearly related to the net transmural flow of NaCl; the solute-linked water flow had a constant hypertonicity in spite of differing net flows of NaCl. The findings are in agreement with the hypothesis of uphill water movement being caused by local osmosis due to the salt flow and with a shunt leak proportional to the transmural osmotic difference. 3. An important part of adaptation to waters of higher salinity is a pronounced increase in the intestinal absorption of NaCl. 4. The osmotic permeability coefficient varied from experiment to experiment without relation to the state of adaptation. An explanation for this finding may be that the osmotic permeability of the intestinal epithelium is of little importance for the total intestinal transfer of water.

Flow along the Gut and Intestinal Absorption of Salt and Water in Euryhaline Teleosts: A Theoretical Analysis

1974 ◽  
Vol 60 (2) ◽  
pp. 557-566
Author(s):  
K. KRISTENSEN ◽  
E. SKADHAUGE
Keyword(s):  
Water Absorption ◽  
Water Flow ◽  
Permeability Coefficient ◽  
Absorption Rate ◽  
Plasma Osmolality ◽  
European Eel ◽  
Drinking Rate ◽  
Osmotic Permeability ◽  
Nacl Absorption ◽  
Concentration Changes

1. In euryhaline teleosts the transmural salt and water flow and the flow and concentration changes along the gut were simulated by analogue computation. The purpose was to elucidate the interaction of and sensitivity to the parameters of the system particularly with respect to intestinal water absorption. The simulations were based on data obtained from the yellow European eel, the rainbow trout and the cyprinodont Aphanius dispar. 2. When the experimental values for drinking rate, maximal NaCl absorption rate and concentration at half-maximal absorption rate, osmotic permeability coefficient, solute-linked water flow, and concentrations in the gut were used in the model, good consistency was achieved, and predictions could be made. 3. The simulations demonstrated a close linkage between drinking rate and maximal NaCl absorption rate. A large water absorption was only possible close to an optimal drinking rate for each value of maximal NaCl transport rate. The water absorption was little sensitive to the osmotic permeability coefficient of the intestinal wall. 4. As a means of adaptation to waters of high salinity an increase in maximal NaCl absorption rate was shown to be very costly for energetic reasons. This supports indirectly the concept that the osmotic permeability of the gills must go down. The increase in plasma osmolality was a useful part of the adaptation.

Kinetics of Water and Chloride Exchanges During Adaptation of the European Eel to Sea Water

1973 ◽  
Vol 58 (1) ◽  
pp. 105-121
Author(s):  
R. KIRSCH ◽  
N. MAYER-GOSTAN
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Maximum Level ◽  
Progressive Increase ◽  
Plasma Sodium ◽  
European Eel ◽  
Drinking Rate ◽  
The One ◽  
Kinetics Of

Using isotopic procedures, the drinking rate and chloride exchanges were studied in the eel Anguilla anguilla during transfer from fresh water to sea water. 1. Following transfer to sea water there is a threefold increase of the drinking rate (lasting about 1 h). Then it falls to a minimum after 12-16 h and rises again to a maximum level about the seventh day after the transfer. Then a gradual reduction leads to a steady value which is not significantly different from the one observed in fresh water. 2. The changes with time of the plasma sodium and chloride concentrations are given. Their kinetics are not completely alike. 3. The chloride outflux increases 40-fold on transfer of the eel to sea water, but even so it is very low. After the sixth hour in sea water there is a progressive increase in the flux, so that on the fourth day it is higher (500 µ-equiv. h-1.100 g-1) than in the seawater-adapted animals (230 µ-equiv.h-1.100 g-1). 4. Drinking rate values in adapted animals are discussed in relation to the external medium. The kinetics of the drinking rate together with variations in body weights after freshwater-seawater transfer are discussed in relation to the possible stimulus of the drinking reflex. 5. Chloride fluxes (outflux, net flux, digestive entry) are compared and lead one to assume that in seawater-adapted fish one-third of the chloride influx enters via the gut and two-thirds via the gills.

RENAL FUNCTION IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.): CHANGES IN BLOOD PRESSURE AND RENAL FUNCTION OF THE FRESHWATER EEL TRANSFERRED TO SEA-WATER

1969 ◽  
Vol 43 (1) ◽  
pp. 9-19 ◽  
Author(s):  
I. CHESTER JONES ◽  
D. K. O. CHAN ◽  
J. C. RANKIN
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Fresh Water ◽  
Inorganic Phosphate ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Urine Flow ◽  
Inulin Clearance ◽  
European Eel ◽  
Clearance Rates

SUMMARY A method for the study of renal function and measurement of mean ventral and dorsal aortic blood pressure for the freshwater and seawater-adapted eel, and during transfer of the animal from fresh water to sea-water, is described. Freshwater eels have higher resting blood pressure, p-aminohippuric acid (PAH) and inulin clearance rates and urine flow than seawater eels. Urine from freshwater animals has low Na, K, Ca, Mg and Cl concentrations, while the clearance rate of inorganic phosphate exceeded that of inulin. Urine from seawater animals has high Na, Ca, Mg and Cl concentrations while that of inorganic phosphate was low. Clearance rates for Ca and Mg greatly exceeded those of inulin. During transfer from fresh water to sea-water there was an initial fluctuation in blood pressure, urine flow and PAH and inulin clearance rates which lasted about 2 hr. Thereafter these gradually declined to values observed for the seawater-adapted animal. The significance of PAH and inulin clearance rates in the study of renal function in the eel and in teleosts in general is discussed.

Temperature-Dependence of Permeability to Water and to Sodium of the Gill Epithelium of the Eel Anguilla Anguilla

1972 ◽  
Vol 56 (3) ◽  
pp. 587-600 ◽  
Author(s):  
R. MOTAIS ◽  
J. ISAIA
Keyword(s):  
Temperature Dependence ◽  
Water Permeability ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Temperature Acclimation ◽  
Osmotic Gradient ◽  
Surprising Result ◽  
Sodium Permeability ◽  
Osmotic Permeability ◽  
Diffusional Permeability

1. The temperature dependence of diffusional permeability to water was studied in freshwater-adapted and seawater-adapted eels. The pattern of temperature acclimation is discussed. 2. The ratio of water permeability to sodium permeability is approximately 3 at 25°C, but falls to 1 at 5°C. This drop is mainly due to a diminution of the water permeability, the temperature coefficients being much higher for water than for sodium. 3. The relatively independent variations of water and sodium permeabilities in the seawater-adapted fish probably indicate a certain dissociation between water movements and salt movements. 4. In the freshwater-adapted eel the osmotic permeability is considerably higher than the diffusional permeability, which supports the previously advanced hypothesis concerning the presence of water-filled channels in the branchial epithelium. 5. In the seawater-adapted eel the osmotic permeability is lower than the diffusional permeability, this difference being greater the lower the temperature. This surprising result must signify either that the osmotic pressure difference between blood and sea water does not represent the true osmotic gradient across the membrane, or that a reabsorption of water linked with a movement of solutes occurs in a specialized region of the gill.

Influence of Ambient Calcium Levels on Tanniocalcin Secretion in the European EEL (Anguilla Anguilla)

1992 ◽  
Vol 162 (1) ◽  
pp. 197-208 ◽  
Author(s):  
R.G.J. M. HANSSEN ◽  
N. MAYER-GOSTAN ◽  
G. FLIK ◽  
S.E. WENDELAAR BONGA
Keyword(s):  
Sea Water ◽  
Secretory Granules ◽  
Anguilla Anguilla ◽  
Secretory Activity ◽  
European Eel ◽  
Apparent Effect ◽  
Rapid Reduction ◽  
Corpuscles Of Stannius ◽  
Rapid Accumulation ◽  
Ionic Calcium

The cells of the corpuscles of Stannius appeared to be more active in eels acclimated to sea water than in eels acclimated to fresh water. In acclimated eels, however, total and ionic plasma calcium concentrations and stanniocalcin titers did not differ. This suggests that levels of stanniocalcin in freshwater-acclimated eels are sufficient to maintain normocalcemia in sea water. When freshwateracclimated eels were transferred directly to sea water, total and ionic calcium concentrations in the plasma increased significantly within 24 h but there was no apparent effect on the corpuscles of Stannius within the same time. This suggests that changes in secretory activity of the corpuscles of Stannius do not occur rapidly when they are presented with a hypercalcemic challenge. Conversely, when seawater-acclimated eels were transferred to fresh or distilled water there appeared to be a very rapid reduction in secretory activity in the corpuscles of Stannius, as indicated by the rapid accumulation of secretory granules. These data suggest that stanniocalcin turnover is more rapid in seawater-acclimated eels and that the secretory activity of the corpuscles of Stannius is rapidly reduced when a hypercalcic challenge is removed.

Plasma Chloride and Sodium, and Chloride Space in the European Eel, Anguilla Anguilla L

1972 ◽  
Vol 57 (1) ◽  
pp. 113-131
Author(s):  
R. KIRSCH
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chloride Concentration ◽  
Anguilla Anguilla ◽  
The Body ◽  
European Eel ◽  
Plasma Chloride ◽  
Sea Water Adaptation ◽  
Sodium Regulation ◽  
High Degree

1. New intra-vascular cannulation techniques are described, and also an extra-corporal blood circuit containing an artificial heart and a counting cell. This makes possible a continuous study of the radioactivity of the blood. 2. Plasma chloride concentration varies greatly in fresh-water eels despite good sodium regulation. 3. The fresh-water to sea-water adaptation of eels is frequently accompanied by a temporary hypermineralization of the internal medium. This necessitates a high degree of cellular euryhalinity. 4. The sea-water-adapted eel maintains strict homeostasis of its plasma chloride and sodium. 5. The chloride distribution space decreases by 10% when eels are transferred from fresh water to sea water. The internal distribution of chloride is also modified and its fluxes between the ion compartments of the body are considerably increased.

Water and ion handling in the rat cecum

1990 ◽  
Vol 259 (5) ◽  
pp. G786-G791 ◽  
Author(s):  
E. Escobar ◽  
C. Ibarra ◽  
E. Todisco ◽  
M. Parisi
Keyword(s):  
Permeability Coefficient ◽  
Driving Force ◽  
Water Movement ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chemical Gradient ◽  
Osmotic Permeability ◽  
Rat Cecum ◽  
Good Agreement

The minute-by-minute net water movement (Jw) in the rat cecum was correlated with the transepithelial potential difference (PD), short-circuit current (Isc), and the unidirectional Na+, Cl-, and Rb+ fluxes, with the following results. 1) Jw was a linear function of the applied hydrostatic or osmotic transepithelial gradients (hydrostatic permeability coefficiency = 0.164 +/- 0.018 cm/s, n = 13; osmotic permeability coefficient = 0.0014 +/- 0.0002 cm/s, n = 6). 2) A fraction of this absorptive Jw (0.17 +/- 0.03 microliter.min-1.cm-2, n = 13) was independent of the presence of any osmotic, hydrostatic, or chemical gradient. 3) This fraction was Na+ dependent, associated with an amiloride-insensitive PD and net Na+ (2.37 +/- 0.68 mu eq.h-1.cm-2, n = 6) and Cl- influxes (3.45 +/- 1.46 mu eq.h-1.cm-2, n = 6), measured under short-circuit conditions. No net Rb+ movement was detected. 4) The absorptive Jw increased when HCO3- was replaced by tris(hydroxymethyl)aminomethane (Tris+) buffer or Cl- by SO4(2-). A good agreement between the observed and the expected Jw (assuming isosmotic reabsorption) was observed in the absence of HCO3-. 5) The presence of an osmotic but not a hydrostatic transepithelial gradient generated a transepithelial PD. These results show that water movement across the rat cecum in vitro is the result of a combination of hydrostatic-, osmotic-, and transport-associated transfers. Concerning this last driving force, the observed results indicate that the transport-related Jw results from the addition of an absorptive Jw, coupled to a nonelectrogenic NaCl entry, plus a secretory Jw probably coupled to HCO3- secretion.

NEUROHYPOPHYSIAL HORMONAL CONTROL OF KIDNEY FUNCTION IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.) ADAPTED TO SEA-WATER OR FRESH WATER

1978 ◽  
Vol 76 (2) ◽  
pp. 347-358 ◽  
Author(s):  
M. M. BABIKER ◽  
J. C. RANKIN
Keyword(s):  
Fresh Water ◽  
Kidney Function ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Hormonal Control ◽  
Arginine Vasotocin ◽  
European Eel ◽  
Urinary Flow ◽  
High Doses ◽  
Freshwater Eels

Low doses of arginine-vasotocin (AVT), isotocin and oxytocin (1 pg–1 ng/kg body weight) were antidiuretic in eels adapted to fresh water but not in those adapted to sea-water. High doses (more than 10 ng/kg) were always diuretic. No effects on tubular water reabsorption were observed and the glomerular filtration rate (GFR) was proportional to the maximum reabsorptive rate for glucose (Tm (glucose)) in eels adapted to sea-water. Increases in urinary flow appeared therefore to result from glomerular recruitment. Infusion of AVT or isotocin at low rates reduced the GFR and urinary flow of freshwater eels to the levels found in seawater eels. Vasopressin (lysine or arginine) had no direct effect on kidney function in freshwater eels but blocked both the diuretic and antidiuretic actions of the other hormones. When infused into seawater eels it was diuretic. This effect could have been due to blockade of the actions of endogenous AVT and/or isotocin.

The biosynthesis of 18-hydroxycorticosterone from exogenous corticosterone by teleost fish adrenocortical tissue in vitro

1970 ◽  
Vol 48 (5) ◽  
pp. 553-558 ◽  
Author(s):  
T. Sandor ◽  
S. W. C. Chan ◽  
J. G. Phillips ◽  
D. Ensor ◽  
I. W. Henderson ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Sea Water ◽  
Kidney Tissue ◽  
Head Kidney ◽  
Anguilla Anguilla ◽  
Melanogrammus Aeglefinus ◽  
European Eel ◽  
Kidney Mitochondria ◽  
Excess Substrate

Incubation of homogenized head kidney tissue of the cod (Gadus morhua) and the haddock (Melanogrammus aeglefinus) with tritiated corticosterone resulted in the formation of small amounts of 18-hydroxycorticosterone (cod 0.04%, haddock 0.012% transformation per 6 g head kidney tissue per 4 h), in the presence of excess NADPH. Incubation of European eel (Anguilla anguilla) posterior vein and head kidney "mitochondria" with corticosterone-4-14C, in the presence of excess substrate and NADPH, also gave rise to 18-hydroxycorticosterone (fresh-water-adapted animals, 0.13% per mitochondria equivalent to 756 mg tissue per 2 h; animals adapted to sea water for 48 h, 0.09% per mitochondria equivalent to 456 mg tissue per 2 h). The biosynthetic, isotopically labelled 18-hydroxycorticosterone was identified by serial oxidation. Head kidneys of both the cod and haddock transformed corticosterone to cortisol. However, the unequivocal presence of aldosterone could not be shown in any of these experiments.

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