Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

The Osmotic and Ionic Regulation of Artemia Salina (L.)

1958 ◽  
Vol 35 (1) ◽  
pp. 219-233 ◽  
Author(s):  
P. C. CROGHAN
Keyword(s):  
Osmotic Pressure ◽  
Sea Water ◽  
Artemia Salina ◽  
Chloride Ions ◽  
The Body ◽  
Distilled Water ◽  
Sodium Potassium ◽  
Rapid Fall ◽  
Water Media ◽  
Potassium Magnesium

1. It has been possible to adapt Artemia to sea-water media varying from 0.26% NaCl to crystallizing brine. In fresh water or distilled water survival is relatively short. 2. The osmotic pressure of the haemolymph is relatively independent of the medium and increases only slightly as the medium is made more concentrated. In the more concentrated media the haemolymph is very markedly hypotonic. In media more dilute than 25% sea water the haemolymph is hypertonic. In distilled water there is a rapid fall of haemolymph concentration. The haemolymph of nauplii from sea water is hypotonic. 3. The sodium, potassium, magnesium, and chloride concentrations of the haemolymph have been determined. The bulk of the haemolymph osmotic pressure is accounted for by sodium and chloride ions. The ionic ratios of the haemolymph are relatively constant, and very different from those of the medium. 4. The concentrations of ions in the whole animal have been studied. The chloride space is extremely high. Such changes in haemolymph osmotic pressure that do occur as the medium concentration is varied are due more to net movements of NaCl into or out of the body than to water movements. 5. Evidence is collected to show that an appreciable degree of permeability exists. Most of this permeability is localized to the gut epithelium, the external surface being much less permeable. 6. It is clear that Artemia must possess mechanisms that can actively excrete NaCl and take up water in hypertonic media. It has been demonstrated that Anemia can lower the haemolymph osmotic pressure by excreting NaCl from the haemolymph against the concentration gradient.

Sodium Regulation and Adaptation to Fresh Water in Gammarid Crustaceans

1968 ◽  
Vol 48 (2) ◽  
pp. 359-380
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Body Weight ◽  
Fresh Water ◽  
Body Surface ◽  
Sea Water ◽  
Sodium Concentration ◽  
The Body ◽  
Outward Diffusion ◽  
Gammarus Zaddachi ◽  
Freshwater Habitats ◽  
Sodium Regulation

1. Sodium uptake and loss rates are given for three gammarids acclimatized to media ranging from fresh water to undiluted sea water. 2. In Gammarus zaddachi and G. tigrinus the sodium transporting system at the body surface is half-saturated at an external concentration of about 1 mM/l. and fully saturated at about 10 mM/l. sodium. In Marinogammarus finmarchicus the respective concentrations are six to ten times higher. 3. M. finmarchicus is more permeable to water and salts than G. zaddachi and G. tigrinus. Estimated urine flow rates were equivalent to 6.5% body weight/hr./ osmole gradient at 10°C. in M. finmarchicus and 2.8% body weight/hr./osmole gradient in G. zaddachi. The permeability of the body surface to outward diffusion of sodium was four times higher in M. finmarchicus, but sodium losses across the body surface represent at least 50% of the total losses in both M. finmarchicus and G. zaddachi. 4. Calculations suggest that G. zaddachi produces urine slightly hypotonic to the blood when acclimatized to the range 20% down to 2% sea water. In fresh water the urine sodium concentration is reduced to a very low level. 5. The process of adaptation to fresh water in gammarid crustaceans is illustrated with reference to a series of species from marine, brackish and freshwater habitats.

The Ionic Relations of Artemia Salina (L.)

1969 ◽  
Vol 51 (3) ◽  
pp. 739-757
Author(s):  
P. G. SMITH
Keyword(s):  
Sea Water ◽  
Electrical Potential ◽  
Artemia Salina ◽  
Electrical Potential Difference ◽  
External Concentration ◽  
Sodium Efflux ◽  
Exchange Diffusion ◽  
Similar Shape ◽  
Diffusional Permeability ◽  
Free Media

I. The effects of different external media on the sodium and chloride efflux in Artemia salina, the brine shrimp, have been observed, using animals acclimatized to sea water. In sea water, both sodium and chloride fluxes across the epithelium are approximately 7,000 pmole cm.-2 sec.-1. 2. Sodium efflux drops markedly in sodium-free media, and chloride efflux falls in chloride-free media; the two effects are independent, and are not due to changes in external osmolarity. 3. The decreases in sodium efflux can be explained by changes in electrical potential difference and diffusional permeability; exchange diffusion of sodium does not occur. 4. Approximately 70% of the chloride efflux is due to exchange diffusion, and most of the remainder is due to active transport. 5. It is shown that graphs of ion efflux against external concentration which can be fitted by a Michaelis-Menten equation do not constitute evidence for the presence of exchange diffusion; graphs of similar shape can be obtained if the flux is simply diffusional. 6. The drinking rate, determined from the rate of uptake of 131I-polyvinylpyr-rolidone, is 36 pl. sec.-1, or 2.0% body weight hr.-1. 7. The diffusional influx of water is 240 pl. sec.-1.

scholarly journals STUDIES IN EDEMA

1910 ◽  
Vol 12 (4) ◽  
pp. 510-532 ◽  
Author(s):  
Moyer S. Fleisher ◽  
Leo Loeb
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Blood Vessels ◽  
Peritoneal Cavity ◽  
Peritoneal Fluid ◽  
Chloride Content ◽  
Body Fluids ◽  
The Body ◽  
Uranium Nitrate ◽  
Rate Of Absorption

I. In normal animals the injection of caffeine slightly diminishes the absorption of fluid from the peritoneal cavity, in spite of the fact that the amount of fluid and sodium chloride eliminated through the kidneys is markedly increased. The lessened absorption of fluid is due to a slight lowering of the osmotic pressure of the blood. II. In nephrectomized animals caffeine increases the absorption of fluid from the peritoneal cavity; the increase in absorption is greater in nephrectomized animals which received caffeine than in nephrectomized animals which did not receive this substance, and it is due to additive increase in the osmotic pressure of the blood. In a similar manner, caffeine increases the absorption of fluid from the peritoneal cavity in animals in which, instead of nephrectomy, other operations, not directly affecting the kidneys, had been performed. In this case also the increase in absorption is presumably preceded by and due to an increase in the osmotic pressure of the blood. III. In animals injected with uranium nitrate three days previously, caffeine diminishes the absorption of fluid from the peritoneal cavity, notwithstanding the high osmotic pressure of the blood which we observe in such animals. This agrees with the results of our previous experiments in which we found that in animals injected with uranium nitrate the absorption of fluid is not increased in spite of the rise of the osmotic pressure of the blood. IV. At the time of the conclusion of the absorption experiments, the amount of fluid retained in the vessels was found to be diminished in each series in which caffeine was used. Only in certain cases can this be due to the increased amount of fluid leaving the blood vessels through the kidneys; in other cases it can only be due to a movement of water from the blood vessels into the tissues caused by the injection of caffeine. V. In normal animals, in nephrectomized animals and in animals in which an operation not directly affecting the kidneys had been performed, caffeine causes an absolute and relative increase in the elimination of sodium chloride from the peritoneal fluid, as a result of which the remaining peritoneal fluid shows a lessened content of sodium chloride. Caffeine causes also a decrease in the sodium chloride content of the blood. We see, therefore, that under the influence of caffeine a greater amount of sodium chloride is eliminated from the body fluids into the tissues or through the kidneys. The factors which cause the sodium chloride to leave the body fluids are probably primarily responsible for the diuresis which takes place after administration of caffeine. In the case of caffeine and other similar substances the diuresis is, therefore, in all probability not due primarily to a specific action of the kidney, but to conditions which affect the distribution of sodium chloride in the body. VI. The distribution coefficient of other osmotically active substances differs from that of sodium chloride. These other substances have a tendency to move into the body fluids in increased quantities under the influence of caffeine. VII. Summarizing all experiments in which we studied the absorption from the peritoneal cavity, we may state that changes in the osmotic pressure of the blood represent the principal factor in explaining the variations in the rate of absorption of fluid from the peritoneal cavity. VIII. There exists no direct relation between an increase in the rate of absorption of fluid from the peritoneal cavity and an increase in the amount of urine secreted. If it should be found that even at a period following the injection of caffeine, later than that at which we have studied the absorption, a rise of the osmotic pressure of the blood does not appear, then we may state that the diminution in the amount of edema in the body cavities resulting from the administration of caffeine is entirely due to an inhibition of the production of edema and not to an increased absorption of fluid from the serous body cavities.

The Diffusion of Chloride Ions in Fly Ash/Cement Pastes and Mortars

1986 ◽  
Vol 85 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy ◽  
P. H. Licastro
Keyword(s):  
Fly Ash ◽  
Water Permeability ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Basic Material ◽  
Fly Ashes ◽  
Cement Pastes ◽  
High Calcium ◽  
Class F

ABSTRACTFly ashes having three distinctly different levels of calcium, designated low-calcium (Class F), intermediate-calcium (Class F/C), and high-calcium (Class C), comprised the basic material for the present study. Pastes and mortars were made using cement and one of three types of fly ashes at various levels of replacement and water-solid ratios. Chloride ion diffusion was measured by applying an electrical potential across cured cylindrical samples and measuring the amount of current passed in a certain period of time (proportional to amount of CE” passed in this time). Other supportive measurements were made, e.g. porosity, pore size distribution, water permeability and surface area. The Cl− ion diffusivity was correlated with the chemical composition of fly ash, mix proportion, and water permeability of the hardened paste or mortar.

scholarly journals Osmolarity-independent electrical cues guide rapid response to injury in zebrafish epidermis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Andrew S Kennard ◽  
Julie A Theriot
Keyword(s):  
Sodium Chloride ◽  
Tissue Injury ◽  
Osmotic Shock ◽  
Ionic Composition ◽  
Electrical Potential ◽  
Chloride Ions ◽  
Wound Response ◽  
Cell Swelling ◽  
Detection Mechanism ◽  
Skin Cells

The ability of epithelial tissues to heal after injury is essential for animal life, yet the mechanisms by which epithelial cells sense tissue damage are incompletely understood. In aquatic organisms such as zebrafish, osmotic shock following injury is believed to be an early and potent activator of a wound response. We find that, in addition to sensing osmolarity, basal skin cells in zebrafish larvae are also sensitive to changes in the particular ionic composition of their surroundings after wounding, specifically the concentration of sodium chloride in the immediate vicinity of the wound. This sodium chloride-specific wound detection mechanism is independent of cell swelling, and instead is suggestive of a mechanism by which cells sense changes in the transepithelial electrical potential generated by the transport of sodium and chloride ions across the skin. Consistent with this hypothesis, we show that electric fields directly applied within the skin are sufficient to initiate actin polarization and migration of basal cells in their native epithelial context in vivo, even overriding endogenous wound signaling. This suggests that, in order to mount a robust wound response, skin cells respond to both osmotic and electrical perturbations arising from tissue injury.

scholarly journals Regulation of Water and Some Ions in Gammarids (Amphipoda)

1971 ◽  
Vol 55 (2) ◽  
pp. 357-369
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Sodium Chloride ◽  
Sea Water ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Body Water ◽  
The Body ◽  
Salinity Range ◽  
Sodium Potassium ◽  
Body Sodium ◽  
Total Body

1. A comparison was made of the body water contents and the concentrations of sodium, potassium and chloride in the blood and body water of Gammarus zaddachi, G. locusta and Marinogammarus finmarchicus. 2. G. zaddachi had a slightly higher body water content than G. locusta and M. finmarchicus. 3. In all three species the blood chloride concentration was lower than the external chloride concentration in 80-113 % sea water, but the blood sodium concentration was equal to or slightly above the sodium concentration in the external medium. 4. The total body sodium concentration was always greater than the total body chloride concentration. In M.finmarchicus the ratio of body sodium/chloride increased from 1.2 to 1.3 over the salinity range 100-20% sea water. In G. zaddachi the ratio of body sodium/chloride increased from 1.08 at 100% sea water to 1.87 in 0.25 mM/l NaCl. 5. The total body potassium concentration remained constant. The potassium loss rate and the balance concentration were relatively high in G. zaddachi. 6. The porportion of body water in the blood space was calculated from the assumption that a Donnan equilibrium exists between chloride and potassium ions in the extracellular blood space and the intracellular space. In G. zaddachi the blood space was equivalent to 60% body H2O at 100% sea water, and equivalent to 50% body H2O at 40% sea water down to 0.5 mM/l NaCl. In M.finmarchicus the blood space was equivalent to 38-44% body H2O at salinities of 20-100% sea water. 7. The mean intracellular concentrations of sodium, potassium and chloride were also calculated. It was concluded that for each ion its intracellular concentration is much the same in the four euryhaline gammarids. The intracellular chloride concentration is roughly proportional to the blood chloride concentration. The intracellular sodium concentration is regulated in the face of large changes in the blood sodium concentration.

The Relative Losses of Sodium in the Urine and Across the Body surface in the Amphipod, Gammarus Duebeni

1965 ◽  
Vol 42 (1) ◽  
pp. 59-69
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Body Surface ◽  
Sea Water ◽  
Average Rate ◽  
The Body ◽  
High Rate ◽  
Water Turnover ◽  
Urine Production ◽  
Sodium Loss ◽  
And Diffusion ◽  
Total Sodium

1. The relative contributions of urine production and diffusion across the body surface to the loss of sodium from the body of the amphipod Gammarus duebeni have been investigated. 2. When the urine is isotonic to the blood some 80% of the total sodium loss is via the urine. 3. As the gradient between blood and medium is increased in dilute media production of urine hypotonic to the blood counteracts the tendency for sodium loss to increase. 4. In consequence, the average rate of sodium uptake at the body surface by animals acclimatized to 2% sea water needs to be only about twice that of animals acclimatized to 50% sea water. 5. It is suggested that the conservation of ions within the body by the production of hypotonic urine is likely to be found to be a common feature of the smaller brackish water crustacea, especially those with a high rate of water turnover.

Potassium metabolism and the accumulation of 137Caesium by decapod Crustacea

1962 ◽  
Vol 42 (2) ◽  
pp. 199-241 ◽  
Author(s):  
G. W. Bryan ◽  
Eileen Ward
Keyword(s):  
Body Surface ◽  
Soft Tissues ◽  
Sea Water ◽  
The Body ◽  
Limiting Factor ◽  
Freshwater Crayfish ◽  
Marine Animals ◽  
Decapod Crustacea ◽  
Concentration Factors ◽  
Potassium Metabolism

SUMMARYThe accumulation of 137Cs from sea water has been examined in relation to potassium metabolism in the lobster Homarus vulgaris and in the prawn Palaemon serratus. In unfed animals 137Cs is taken up and lost far more slowly than 42K. Although all the inactive K in the animals can be exchanged with 42K, higher whole-animal concentration factors are reached for 137Cs (about eight for lobsters and twenty-five for prawns). This is because both species have higher plasma/medium ratios for 137Cs than K at equilibrium despite the selective excretion of 137Cs. Also, except for the hepatopancreas in lobsters and fed prawns, all soft tissues can probably attain higher tissue/plasma ratios for 137Cs than inactive K.Uptake of both isotopes has also been studied in the freshwater crayfish Austropotamobius pallipes pallipes. In crayfish in o-i % sea water 137Cs is not concentrated to the same extent as K by whole animals (50-200 for 137Cs against about 4500 for K). Although the situation between plasma and tissues resembles that in the marine animals, 137Cs cannot be accumulated in the plasma to the same degree as K. Crayfish selectively excrete 137Cs in the urine relative to K at a lower concentration than in the plasma.In the accumulation of 137Cs by all species, muscle is the principal limiting factor in uptake and loss, but with 42K the body surface becomes more limiting.Experiments on the absorption of 137Cs from food in prawns and freshwater crayfish have been carried out. In prawns in a constant environment, feeding is probably less important than uptake over the body surface while in crayfish feeding is probably much more important.

The Permeability of Chloride Ions in Fly Ash-Cement Pastes, Mortars and Concrete

1987 ◽  
Vol 114 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Ionic Species ◽  
Cylindrical Sample ◽  
Chloride Ions ◽  
Test Scheme ◽  
Chloride Permeability ◽  
Experimental Conditions ◽  
Cement Pastes

ABSTRACTFly ash-cement pastes are known to develop fine pore structures that may retard the transport of ionic species. The rapid chloride permeability technique for studying the Cl− ion diffusion in hydrated fly ash/cement pastes, mortars and concrete was used. The technique applies an electrical potential across a cylindrical sample and measures the charge passed in a certain period of time. The results obtained on pastes and mortars cured for 28 days were reported previously and contrasted with those of neat cement pastes and mortars. The present paper reports more extensive studies made to examine the chloride permeabilities of pastes and mortars cured for up to 90 days. In addition, the effect of variable fly ash contents was examined. Concrete samples were included in the test scheme and the data were compared with pastes and mortars. Two important factors controlling the test results are discussed: first the mix design and curing conditions; second the experimental conditions during Cl− permeability measurements. In the second factor, the amount and rate of heat build up and the chloride ion concentrations are compared with the current passed. In addition, measuring current versus resistivity are critically discussed in terms of the voltage-current varistic characteristics of cement matrices.

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