Urine composition and kidney tubular function in southern flounder, Paralichthys lethostigma, in sea water

1968 ◽  
Vol 46 (3) ◽  
pp. 439-455 ◽  
Author(s):  
Cleveland P. Hickman Jr.
Keyword(s):  
Sea Water ◽  
Potassium Phosphate ◽  
Secretory Activity ◽  
Urine Flow ◽  
Divalent Ions ◽  
Average Percentage ◽  
Southern Flounder ◽  
Monovalent Ions ◽  
Urine Composition ◽  
Millimolar Concentration

Magnesium, sulfate, and chloride make up approximately 80% of the total millimolar concentration of major electrolytes in the urine of southern flounder in seawater, The remaining major electrolytes present are calcium, sodium, potassium, phosphate, and an unknown anion component. As a rule, more sodium was present when urine flow was very low: phosphate concentration was highly variable but its concentration was not associated with urine flow. Urine composition was independent of the glomerular filtration rate. With one exception, the urine osmolality was substantially less than the millimolar concentration, because of the low activities of the divalent ions present and because some of the urine calcium and phosphate precipitated out of solution. The urine was usually 5–15 mosmoles hypoosmotic to the blood; it occasionally became slightly hyperosmotic to the blood for a brief interval after operative procedures.The average percentage filterabilities of the plasma electrolytes, determined by centrifugal ultrafiltration, were Na, 78.4%; Cl 91.1%; K, 88.0%;Ca, 18.5%; Mg, 54.6%; PO4, 48.7%. Calculation of the quantities of electrolytes filtered, reabsorbed, secreted, and excreted showed that the urine is primarily a product of tubular secretory activity, but that at high filtration rates the absolute quantities of monovalent ions reabsorbed by the tubular epithelium may greatly exceed the quantities of divalent ions secreted. The divalent ion secretory mechanism was found to respond sensitively and specifically to ion loading produced by MgCl2 infusion or exposure to concentrated seawater. The possible location of specific ion reabsorptive and secretory activities and differences in tubular permeability to water is discussed in relation to the known morphology of the kidney.

Osmoregulation of Lampetra Fluviatilis L. and Petromyzon Marinus (Cyclostomata) in Hyperosmotic Solutions

1970 ◽  
Vol 53 (1) ◽  
pp. 231-243
Author(s):  
ALAN D. PICKERING ◽  
R. MORRIS
Keyword(s):  
Alimentary Canal ◽  
Sea Water ◽  
Petromyzon Marinus ◽  
Urine Flow ◽  
Sodium Potassium ◽  
Monovalent Ions ◽  
Anadromous Migration ◽  
Calcium Magnesium ◽  
High Concentrations ◽  
Osmoregulatory Mechanism

1. Freshly caught migrating lampreys were placed in 50% sea water and their method of osmoregulation was analysed. Some osmoregulated more successfully than others. 2. Water balance is maintained by a mechanism involving the drinking of large quantities of water (up to 99.5 ml/kg/day). Sodium, potassium and chloride are absorbed by the intestine (often against a concentration gradient) with the subsequent uptake of water. Divalent ions are not readily absorbed by the intestine and there is some evidence for the secretion of magnesium and sulphate into the gut lumen. 3. The limited urine flow (up to 6.2 ml/kg/day) is used for the excretion of calcium, magnesium and sulphate in high concentrations, but the urine is never hyperosmotic to the blood. The urinary excretion of monovalent ions is not sufficient to eliminate those entering by the intestine and extrarenal excretion at the gills must presumably occur. 4. The breakdown of this osmoregulatory mechanism during the anadromous migration involves: an increase in the permeability of the integument to water, breakdown of the swallowing mechanism which is not dependent upon the occlusion of the alimentary canal, a reduction in the ability to absorb monovalent ions and water from the ingested 50% sea water, and a loss in the large mitochondria-rich ‘chloride output cells’ of the gills. 5. The similarities between the mechanisms of ‘marine’ osmoregulation of lampreys and teleosts are discussed in terms of the evolution of the two groups, and it is concluded that almost identical osmoregulatory mechanisms have evolved independently.

Kidney Function in the Crab-Eating Frog (Rana Cancrivora)

1962 ◽  
Vol 39 (1) ◽  
pp. 167-177 ◽  
Author(s):  
KNUT SCHMIDT-NIELSEN ◽  
PING LEE
Keyword(s):  
East Asia ◽  
Glomerular Filtration ◽  
Kidney Function ◽  
Sea Water ◽  
Tubular Reabsorption ◽  
Urine Flow ◽  
South East Asia ◽  
Considerable Part ◽  
Osmotic Concentration ◽  
Full Strength

1. A study has been made of kidney function in the crab-eating frog, Rana cancrivora, of south-east Asia. 2. This frog can live in full-strength sea water; in such concentrated media its blood is slightly hypertonic to the medium, and a considerable part of the osmotic concentration is due to urea. 3. In concentrated media the excretion of urea is greatly diminished. This is not due to active tubular reabsorption of urea, but primarily to a low urine flow caused by increased tubular reabsorption of water and reduced glomerular filtration. 4. In concentrated media, as compared with dilute media, only a few percent of the filtered urea appears in the urine. 5. Osmoregulation of the crab-eating frog in sea water resembles that of elasmobranchs except in that there is no evidence of active tubular reabsorption of urea in the frog.

A Micropuncture Study of Kidney Function in the River Lamprey Lampetra Fluviatilis Adapted to Sea Water

1980 ◽  
Vol 88 (1) ◽  
pp. 239-248
Author(s):  
A. G. LOGAN ◽  
R. MORRIS ◽  
J. C. RANKIN
Keyword(s):  
Fresh Water ◽  
Kidney Function ◽  
Sea Water ◽  
Chloride Ions ◽  
Water Reabsorption ◽  
Plasma Electrolyte ◽  
River Lamprey ◽  
Micropuncture Study ◽  
Urine Composition ◽  
High Concentrations

Micropuncture techniques have been used to investigate kidney function in lampreys adapted to hyperosmotic media. Plasma electrolyte concentrations were maintained well below corresponding concentrations in the external environment. Urine composition was variable, but generally showed high concentrations of magnesium, sulphate and chloride ions. Lampreys in 50% sea water produced urine which was hypo or iso-osmotic to plasma, whereas those in 100% sea water produced hyperosmotic urine. Urine flow rate in 50% sea water was one tenth of that in fresh water, due to a reduction in filtration rate and an increase in water reabsorption by the kidney. As in fresh water, little if any filtered water was reabsorbed by the proximal segment. Almost 90% of filtered water was reabsorbed by the kidney of 100% sea water lampreys and most of this must have occurred in the distal and collecting segments.

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.

scholarly journals MODIS observed phytoplankton dynamics in the Taiwan Strait: an absorption-based analysis

2011 ◽  
Vol 8 (4) ◽  
pp. 841-850 ◽  
Author(s):  
S. Shang ◽  
Q. Dong ◽  
Z. Lee ◽  
Y. Li ◽  
Y. Xie ◽  
...  
Keyword(s):  
Coastal Upwelling ◽  
Sea Water ◽  
River Estuary ◽  
Taiwan Strait ◽  
Percentage Error ◽  
Nutrient Loads ◽  
Phytoplankton Dynamics ◽  
Average Percentage ◽  
The Taiwan Strait

Abstract. This study used MODIS observed phytoplankton absorption coefficient at 443 nm (Aph) as a preferable index to characterize phytoplankton variability in optically complex waters. Aph derived from remote sensing reflectance (Rrs, both in situ and MODIS measured) with the Quasi-Analytical Algorithm (QAA) were evaluated by comparing them with match-up in situ measurements, collected in both oceanic and nearshore waters in the Taiwan Strait (TWS). For the data with matching spatial and temporal window, it was found that the average percentage error (ε) between MODIS derived Aph and field measured Aph was 33.8% (N=30, Aph ranges from 0.012 to 0.537 m−1), with a root mean square error in log space (RMSE_log) of 0.226. By comparison, ε was 28.0% (N=88, RMSE_log = 0.150) between Aph derived from ship-borne Rrs and Aph measured from water samples. However, values of ε as large as 135.6% (N=30, RMSE_log = 0.383) were found between MODIS derived chlorophyll-a (Chl, OC3M algorithm) and field measured Chl. Based on these evaluation results, we applied QAA to MODIS Rrs data in the period of 2003–2009 to derive climatological monthly mean Aph for the TWS. Three distinct features of phytoplankton dynamics were identified. First, Aph is low and the least variable in the Penghu Channel, where the South China Sea water enters the TWS. This region maintains slightly higher values in winter (~17% higher than that in the other seasons) due to surface nutrient entrainment under winter wind-driven vertical mixing. Second, Aph is high and varies the most in the mainland nearshore water, with values peaking in summer (June–August) when river plumes and coastal upwelling enhance surface nutrient loads. Interannual variation of bloom intensity in Hanjiang River estuary in June is highly correlated with alongshore wind stress anomalies, as observed by QuikSCAT. The year of minimum and maximum bloom intensity is in the midst of an El Niño and a La Niña event, respectively. Third, a high Aph patch appears between April and September in the middle of the southern TWS, corresponding to high thermal frontal probabilities, as observed by MODIS. Our results support the use of satellite derived Aph for time series analyses of phytoplankton dynamics in coastal ocean regions, whereas satellite Chl products derived empirically using spectral ratio of Rrs suffer from artifacts associated with non-biotic optically active materials.

On the structure and function of the urogenital system of the female lumpsucker Cyclopterus lumpus L. (Teleostei: Scorpaeniformes)

1983 ◽  
Vol 218 (1211) ◽  
pp. 201-210 ◽  
Keyword(s):  
Sea Water ◽  
Bladder Wall ◽  
Structure Type ◽  
Large Female ◽  
Type I ◽  
Urogenital System ◽  
Divalent Ions ◽  
Ovarian Fluid ◽  
Cyclopterus Lumpus ◽  
And Function

The ovaries and oviducts of female lumpsuckers, Cyclopterus lumpus L., are fused to form a single sac which is strongly bifurcated anteriorly. The oviduct is very wide and guarded by a powerful sphincter. The ovarian fluid surrounding the eggs of ripe hen fish is copious (> 500 ml) and contains very low concentrations of Mg 2+ and Ca 2+ (necessary because divalent ions cause eggs to harden and stick together). It is suggested that large amounts of ovarian fluid may provide a fluid barrier between unspawned eggs and sea water during the expulsion of egg masses (females lay one to three masses at intervals of 8–10 days). The kidney of Cyclopterus is a single structure (type I according to the classification of Ogawa ( Sci. Rep. Tokyo Kyoidu Daigaku B 10, 61–68 (1961)), but there are two ureters’ which deliver urine to a urinary bladder. A short ‘urethra’ runs from the bladder to the exterior; urethra, oviduct and rectum all open separately to the exterior. Female lumpsuckers possess large urinary bladders which have roughly five times the volume of the bladders of male fish (allowing for the sexual size dimorphism of the species). Evidence is presented to show that the bladder probably has a water resorptive function based upon the pumping of Na + across the bladder wall in the mucosal to serosal direction. The large female bladder appears to be necessary to cope with the problems of storage and water resorption caused by the enhanced urine flow needed to excrete divalent ions and thus maintain low Mg 2+ and Ca 2+ concentrations in blood and ovarian fluid.

scholarly journals The Chemical Composition and the Acid Base Balance of Archidoris Britannica

1937 ◽  
Vol 22 (1) ◽  
pp. 273-280 ◽  
Author(s):  
R. A. McCance ◽  
M. Masters
Keyword(s):  
Sea Water ◽  
Potassium Phosphate ◽  
The Body ◽  
Mineral Matter ◽  
Acid Base Balance ◽  
Visceral Mass ◽  
Base Balance ◽  
Inorganic Composition ◽  
Calcium And Magnesium ◽  
High Concentrations

The body of Archidoris britannica contains very high concentrations of calcium and magnesium which appear to be combined mostly with CO3 and fluoride. The bulk of these materials are in solid deposits throughout the submucous tissue. Sodium chloride and potassium phosphate account for most of the residual mineral matter.The mucus secreted by the body has an inorganic composition resembling sea water.The visceral mass contains only one-tenth as much calcium and magnesium as the body. The predominating bases are potassium and sodium and the acid radicles are essentially chlorides and phosphates.

Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH

1975 ◽  
Vol 270 (908) ◽  
pp. 301-318 ◽  
Keyword(s):  
Charge Density ◽  
Sodium Channel ◽  
Surface Charge ◽  
Diffuse Double Layer ◽  
Divalent Ions ◽  
Fixed Charges ◽  
Tenfold Increase ◽  
Monovalent Ions ◽  
Negative Surface ◽  
Negative Surface Charge

Evidence is given for a high density of negative surface charge near the sodium channel of myelinated nerve fibres. The voltage dependence of peak sodium permeability is measured in a voltage clamp. The object is to measure voltage shifts in sodium activation as the following external variables are varied: divalent cation concentration and type, monovalent concentration, and pH. With equimolar substitution of divalent ions the order of effectiveness for giving a positive shift is: Ba = Sr < Mg < Ca < Co ≈ Mn < Ni < Zn. A tenfold increase of concentration of any of these ions gives a shift of + 20 to + 25 mV. At low pH, the shift with a tenfold increase in Ca 2+ is much less than at normal pH, and conversely for high pH. Solutions with no added divalent ions give a shift of — 18 mV relative to 2 mM Ca 2+ . Removal of 7/8 of the cations from the calcium-free solution gives a further shift of — 35 mV. All shifts are explained quantitatively by assuming that changes in an external surface potential set up by fixed charges near the sodium channel produce the shifts. The model involves a diffuse double layer of counterions at the nerve surface and some binding of H+ ions and divalent ions to the fixed charges. Three types of surface groups are postulated: (1) an acid p K a = 2.88, charge density —0.9 nm -2 ; (2) an acid p K a = 4.58, charge density —0.58 nm -2 ; (3) a base p K a = 6.28, charge density + 0.33 nm -2 . The two acid groups also bind Ca 2+ ions with a dissociation constant K = 28 M. Reasonable agreement can also be obtained with a lower net surface charge density and stronger binding of divalent ions and H + ions.

The Physiology of the Antennal Gland of Carcinus Maenas (L.)

1969 ◽  
Vol 51 (1) ◽  
pp. 11-16
Author(s):  
R. BINNS
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Urine Flow ◽  
The Body ◽  
Antennal Gland ◽  
Urine Production ◽  
The Mean ◽  
Gland Function ◽  
Water Clearance

1. The space measured by inulin distribution, the ‘inulin volume’, has been determined, and represents approximately 20% of the body weight in crabs ranging in size from 20.0 to 57.2 g. 2. After the injection of labelled inulin into crabs, the increase in activity of the medium is equal to the fall in blood inulin in all dilutions of sea water. Clearance of inulin from the blood is due only to urine production, and therefore the molecule can be used for quantitative investigations of antennal gland function. 3. Urine production in various concentrations of sea water has been determined by measuring the clearance of inulin from the blood and the rates at which the tracer appeared in the external media. By these methods the mean rate of urine production in 100% sea water was estimated to be 4.4% body weight per day. In dilute sea water the rate of urine production increases; for example, in 50% sea water the urine flow is four times greater than in normal sea water.

The Effects of Prolactin and Divalent Ions on the Permeability to Water of Fundulus Kansae

1970 ◽  
Vol 53 (2) ◽  
pp. 317-327 ◽  
Author(s):  
W. T. W. POTTS ◽  
W. R. FLEMING
Keyword(s):  
Fresh Water ◽  
Calcium Ions ◽  
Sea Water ◽  
Tritiated Water ◽  
Low Doses ◽  
Divalent Ions ◽  
Water Turnover ◽  
Drinking Rate ◽  
Low Concentration ◽  
Ovine Prolactin

1. Measurements have been made of the rate of exchange of tritiated water in both intact and hypophysectomized Fundulus kansae in a variety of media. 2. Hypophysectomy reduces the rate of exchange in fresh water. 3. Low doses (30 mu) of ovine prolactin stimulate water turnover in hypophysectomized fish in fresh water. 4. The rate of exchange declines in both intact and hypophysectomized animals with increasing salinity. 5. Experiments with synthetic solutions show that the decline in the rate of exchange in sea water and in higher salinities is due mainly to the effects of calcium ions. 6. Fishes maintained in synthetic sea water containing a low concentration of calcium have both a higher rate of exchange of tritiated water and a higher drinking rate than fish in normal sea water.

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