The partial double Donnan—A simple alternative interpretation of the transmembrane ionic distribution

• 1.1. The pump-leak hypothesis of transmembrane ion distribution implicitly poses the operational immobilization of a fraction of intracellular potassium and extracellular sodium.
• 2.2. Subtraction of operationally immobilized ion fractions from total intracellular potassium and extracellular sodium concentrations leads to Donnan ratios of the mobile fractions consistent with the transmembrane distribution of the chloride ions and potentials derived from the constant field equation.
• 3.3. The predictions of this simple approach agree with the experimental observations regarding ionosmotic processes in several types of aquatic animal cells.

     

Ascorbate (vitamin c) and dehydroascorbate stimulation of copper induced hemolysis protective action of ceruloplasmin,albumin and apotransferrin

• 1.1. Copper ion induced lysis of rat erythrocytes was markedly stimulated by low concentrations of ascorbate and dehydroascorbate.
• 2.2. Ascorbate oxidase, superoxide dismutase, catalase or scavengers of hydroxyl radicals protected erythrocytes against copper-ascorbate stimulated lysis.
• 3.3. It is proposed that superoxide radicals and hydrogen peroxide cooperate in producing hydroxyl radicals, which are directly involved in hemolysis.
• 4.4. The serum proteins, ceruloplasmin. albumin and apotransferrin, also reduced the hemolytic action of copper-ascorbate, the order of effectiveness being; ceruloplasmin > albumin > apotransferrin.

     

The effect of reduced salinity on tissue and plasma composition of the dogfish,Squalus acanthias

• 1.1. Dogfish (Squalus acanthias) were acclimated to reduced salinities and their plasma, muscle tissue and erythrocytes subsequently analysed.
• 2.2. Decrease in the osmolarity of the plasma was principally due to a fall in urea concentration and a significant fall in the concentrations of sodium and chloride.
• 3.3. Changes in the muscle and erythrocytes in dilute media were a decrease in urea, potassium, sodium and chloride concentrations.
• 4.4. The concentrations of the free amino acids in the muscle and the red blood cells decreased more than would be expected by the movements of water only.
• 5.5. The results were discussed in relation to the regulation of cellular volume and the involvement of the free amino acid pool of the tissues in this process.

     

Examination of water balance and ionic regulation in the earthworm,Eisenia foetida

• 1.1. Weight change after submerging the earthworm into water varied remarkably according to the environmental humidity in which animals were placed before submergence.
• 2.2. Pretreatment with physiological saline solution before submergence in water gave stable values for the ionic concentrations of the body fluid.
• 3.3. Brain removal caused decrease of both sodium and chloride ion concentrations and increase of potassium ion concentration of the coelomic fluid when animals were submerged in water.
• 4.4. Although brain replacement failed, action of a brain hormone is suggested to regulate the decrease of both sodium and choride ions and increase of potassium ion of the coelomic fluid to normal level when animals were submerged in water.

     

The protective action of ceruloplasmin on Fe2+ stimulated lysis of rat erythrocytes

• 1.1. Ceruloplasmin, a copper containing serum protein, was found to effectively protect washed rat erythrocytes against Fe²⁺ stimulated lysis.
• 2.2. It is proposed that Ceruloplasmin, through its Fe²⁺ oxidase activity, prevents the formation of superoxide radicals, known to cause hemolysis.

     

Driving forces for the uphill transport of amino acids into epidermal brush border membrane vesicles of the sea anemone,Anemonia sulcata (Cnidaria,anthozoa)

• 1.1. The transport of amino acids into membrane vesicles prepared from epidermal tentacle tissue of the sea anemone, Anemonia sulcata, depends on an electrochemical potential difference caused, e.g. by sodium chloride gradients.
• 2.2. Potassium or choline chloride gradients energized the transport less effectively than sodium chloride gradients. Both Na⁺-ions and Cl⁻-ions were required for the amino acid transport.
• 3.3. The uphill transport of amino acids along the downhill movement of driver ions (sodium chloride gradient conditions) was characterized by an overshoot; under sodium chloride equilibrium conditions, however, an accumulation of amino acids within the vesicles could not be measured.
• 4.4. Potassium diffusion potentials in combination with valinomycin indicated that hyperpolarization (vesicle inside negative) and hypopolarization (vesicle inside positive) enhanced or depressed the accumulation of amino acids within the vesicles.
• 5.5. Being at the phylogenetic base of the Eumetazoa, cnidarians show characteristics for the transmembrane transport of amino acids comparable to those established for vertebrates.

     

The effect of osmotic and ion-osmotic stresses on the blood and urine composition and urine flow of rainbow trout (Salmo gairdneri)

• 1.1. Changes in urine and plasma concentrations (sodium, potassium, magnesium, calcium and total osmotic) and urine production were determined in fish exposed to various concentrations of an ionically active substance, sodium chloride, and a non-electrolyte, mannitol, as well as freshwater.
• 2.2. Responses occurred for the most part over a short crisis period preceeding establishment of new stable conditions.
• 3.3. It was shown that plasma homeostasis was not maintained in response to changing ion-osmotic and osmotic gradients.
• 4.4. Urinary osmotic and ionic concentrations were unaffected and urine production was shown to be inversely related to the external concentration.
• 5.5. It is suggested that ionic shifts between body compartments are an important aspect of ion-osmotic adaptation.

     

Comparative hematology: Studies on cats including one with factor XII (hageman) deficiency

• 1.1. Cat plasma prothrombin and partial thromboplastin times are faster than human. Thromboplastin generation tests are very similar.
• 2.2. Factors VIII and V assay 24 and 13 times the human standard. Cat factors VII, X. IX, XI and XII assayed at 2.5 to 4 times human. Factors I, II and XIII fell within the human range and Fletcher was extremely low.
• 3.3. One cat lacked factor XII and showed a prolonged APTT and clotting time.
• 4.4. Cat profibrinolysin was activated by streptokinase but not by urokinase.
• 5.5. Cat platelets aggregated with the usual human aggregation agents with the exception of thrombin and ristocetin.
• 6.6. Cat erythrocytes were smaller and more numerous than human.
• 7.7. Leukocyte counts were quite variable.
• 8.8. Serum protein electrophoretic patterns differed from human in the greater migration of albumin and the presence of numerous unidentified bands.
• 9.9. Biochemical tests showed high sodium and chloride values.

     

Short-term osmotic responses of cells and tissues of the sea anemone,Condylactis gigantea

• 1.1. Cells of tentacles and body wall of the sea anemone Condylactis gigantea behaved as simple osmometers during 5hr exposure to 50, 67, 83, 100 and 125% sea-water.
• 2.2. All intracellular water appeared to be osmotically active.
• 3.3. Cell sodium, chloride and total osmolyte content remained invariable, with taurine decreasing and potassium increasing as sea-water concentration was reduced.
• 4.4. Tissues, as a whole, exhibited a pseudoregulatory response to changes in salinity as the large and osmotically inert extracellular space buffered volume changes to a considerable extent.

     

The role of extracellular sodium in isosmotic intracellular regulation in the respiratory tree of Holothuria glaberrima

• 1.1. Respiratory trees of Holothuria glaberrima exposed to solutions in which sodium has been replaced by choline, Tris pH 6.1, Tris pH 8.0 or lithium show a net loss of intracellular water, potassium, sodium and chloride. Intracellular content of neutral orgainc osmotic effectors remains unmodified.
• 2.2. Extracellular lithium and Tris pH 8.0 decrease intracellular potassium concentration to half that in sodium, choline and Tris pH 6.1. Intracellular sodium concentration falls markedly while that of chloride falls moderately in sodium-free solutions. Sodium substitutes appear to enter the cells.
• 3.3. A model based on Donnan considerations accounts for the patterns of ion and water distribution.

     

Whole-cell outward currents in freshly dissociated rat placental cells

• 1.1.We applied whole cell voltage clamp techniques to freshly dissociated rat placental cells (20–21 days gestation). Tetraethylammonium (TEA)-sensitive outward currents were recorded in about 50% of cells.
• 2.2.The outward current had a reversal potential of -50mV which is more positive than the potassium equilibrium potential (−82mV).
• 3.3.The bath solution without NaCI decreased the outward current amplitude, while the elimination of only Na ions from the bath solution did not modify the outward current.
• 4.4.The results suggest a possible contribution of chloride ions to the outward currents in rat placental cells.

     

Immobilization stress-induced antioxidant defense changes in rat plasma: Effect of treatment with reduced glutathione

• 1.1. We examined immobilization stress-induced antioxidant defense changes in rat plasma and observed the antioxidant effect of reduced glutathione (GSH) administration on these changes.
• 2.2. Immobilization stress induced severe bleeding in the stomach and a significant increase in plasma levels of thiobarbituric acid receives substances (TBARS).
• 3.3. Immobilization stress induced a significant decrease in plasma iron-binding, ironoxidizing protections and radical scavenging activity.
• 4.4. Plasma levels of ascorbic acid, ascorbyl radical and superoxide dismutase activity remained unchanged following immobilization stress.
• 5.5. Treatment with GSH showed a significant protective effect on stomach bleeding, on the increase in plasma TEARS, and on the decrease of iron-binding, iron-oxidizing protection and radical scavenging activity in plasma.
• 6.6. These results suggest that immobilization stress induces generation of reactive oxygen species and decreases the endogenous antioxidant defenses, which can be attenuated by extracellular administration of antioxidant GSH.

     

Isolation of dna and rna from Streptococcus sobrinus OMZ176 using CsTFA gradients

• 1.1. A simple procedure for isolation of high molecular weight genomic DNA, and RNA, from Streptococcus sobrinus OMZ176 is described.
• 2.2. Cell cultures were grown aerobically for 10 hr.
• 3.3. Spheroplast formation and lysis was achieved by mutanolysin/lysozyme-dependent digestion of the cell wall, followed by N-lauroylsarcosinate-mediated lysis.
• 4.4. Nucleic acids were isolated directly from cell-lysates using cesium-trifluoroacetate (CsTFA) densitygradient centrifugation.
• 5.5. Three different centrifugation regimes were tested: self-generated density gradients in a fixed angle rotor; self-generated density-gradients in a swinging-bucket rotor; pre-formed density-gradients in a swinging-bucket rotor.
• 6.6. Genomic DNA isolated by the CsTFA-procedure was found to have higher purity as compared to genomic DNA isolated in a conventional CsCl gradient.
• 7.7. Isolated DNA was shown to be of a quality suitable for applications in molecular biology.

     

The effect of feed restriction on certain haematological indices,enzymes and metabolites in Nubian goats

• 1.1. Some effects of restricting feed intake for 96 or 168 hr were determined in male Nubian goats.
• 2.2. Goats restricted for 96 hr lost 11.6% of their body weight, and goats restricted for 168 hr lost 19.8%.
• 3.3. Feed restriction for up to 168 hr did not produce significant effects on the heart rate, respiratory rate or rectal temperature.
• 4.4. Haemoglobin concentration, packed cell volume and erythrocyte number were all decreased by feed restriction. There was also a tendency towards eosinopenia and lymphopenia.
• 5.5. Feed restriction for 96 or 168 hr raised the plasma activity of aspartate transaminase, and did not affect significantly cholinesterase activity. Plasma amine oxidase activity was significantly reduced in goats restricted for 168 hr.
• 6.6. Feed restriction produced significant increases in the blood or plasma concentrations of lactate. pyruvate, non-esterified fatty acids, cholesterol, ketone bodies and bilirubin.
• 7.7. Significant decreases were found in the concentrations of total protein and calcium.
• 8.8. No significant changes were observed in the plasma concentrations of glucose, sodium or potassium.

     

Salt and water balance in the sipunculan phascolopsis gouldi: is any animal a “simple osmometer”?

• 1.1. Phascolopsis gouldi, the commonly studied sipunculan of the Woods Hole area, Massachusetts, can tolerate a salinity range from about 45% seawater to at least 100% SW, with literature records extending to about 160% SW. There was no survival at 40% SW.
• 2.2. Over this salinity range, P. gouldi is an osmotic and ionic conformer.
• 3.3. The osmotic and sodium concentrations of the coelomic fluid are the same as that of the medium; the chloride concentration is about 9% less than that of the medium; the potassium concentration is about 30% higher.
• 4.4. Analysis of water content regulation by two different approaches shows that P. gouldi does have a limited ability for volume regulation, restricted to salinities higher than 58% SW.
• 5.5. P. gouldi is not a “simple osmometer”.

     

Seasonal changes of water,electrolytes and aldosterone levels in blood serum,brain and kidney of the Egyptian cobra “Naja haje haje”

 

• 1.The levels of water, Na, K, Ca and Mg in blood serum, brain and kidney and aldosterone level in blood of Naja haje haje were studied during the different phases of the annual cycle.
• 2.The water content in the tissues studied displayed only minor changes as the animals passed from one phase to the other.
• 3.A significant increase in Na was recorded in the brain during the different phases indicating a depressed sodium pump, whereas the blood Na level showed a significant decrease during hibernation.
• 4.K increased in blood serum, brain and kidney during hibernation, while a nonsignificant decrease was found in blood serum during arousal. The brain may act as a potassium reservoir.
• 5.An increase in Ca and Mg concentration was recorded in blood serum, brain and kidney during prehibernation and hibernation. The data suggested a homeostatic function in the transport and metabolism of these cations.
• 6.Aldosterone exhibited a highly significant decrease especially during hibernation. The aldosterone regulation of ionic composition is discussed.
• 7.Na/K and Ca/Mg ratios in the brain may explain the decreased excitability during winter torpor.

     

Biochemical studies in a eunicid (polychaete) of the littoral of São Paulo,Brazil

• 1.1. The sodium, potassium, chloride, calcium, magnesium, phosphorus, sulphur, copper, iron, total carbon dioxide, uric acid, creatinine, urea, glucose, erythrocruoin, nitrogen, total iodine, protein-bound iodine, total lipids, triglycerides, alkaline phosphatase activity, acid phosphatase activity and copper oxidase activity contents of the blood of the giant Polychaete, Eunice sp., were determined.
• 2.2. The osmolarity of the blood was 997 mOsm/1 and the pH was 6·49, a very low value. The bicarbonate concentration estimated by the Henderson-Hasselbach equation was 4·70 mM/1.
• 3.3. The values of the sea water, sediments, water contained in the tube, tube, cuticle, muscle and faeces are also given.
• 4.4. The chemical composition of the mucus was determined.

     

Salinity tolerance and sodium balance in the prawn Palaemonetes vulgaris (say) compared with P. pugio

• 1.1. Larvae (first zoeae) of Palaemonetes vulgaris are relatively stenohaline (optimum salinity = 20%.), adults euryhaline (96-hr LD₅₀ values: 0.8 and 51%.).
• 2.2. The concentration of blood sodium remains nearly constant over the salinity range 5–45%.
• 3.3. Adult P. vulgaris are less tolerant of dilute (1–20%.) media than sympatric P. pugio but equally tolerant of higher salinities (35–45%.). Palaemonetes vulgaris maintains a slightly more constant and higher (average) sodium concentration in the blood than P. pugio.
• 4.4. It is suggested that these differences contribute to habitat partitioning of these species and that they reflect the greater affinity of P. vulgaris for a euhaline milieu.

     

Blood changes in japanese eels,Anguilla japonica,experimentally infected with typical or atypicalAeromonas salmonicida

• 1.1. Changes in the blood and in the rate of oxygen consumption of Japanese eels injected intramuscularly in the head with a lethal dose of typical or atypical Aeromonas salmonicida at 20°C were investigated.
• 2.2. Eels infected with the bacteria became moribund within 4 to 6 days, and then died within 1 day.
• 3.3. The O₂ consumption rate and blood parameters changed markedly with infections. The responses of hosts to infection by the two kinds of bacteria differed with regard to the following four points: blood pH, plasma Cl⁻, lactic acid, and the numbers of granulocytes and lymphocytes.
• 4.4. The responses of eels infected with atypical A. salmonicida were larger and more rapid than those of eels infected with typical A. salmonicida.

     

Osmotic changes in an estuarine bivalve,Modiolus fluviatilis

• 1.1.Responses to different salinities monitored by opening and closing of the shell valves were observed in Modiolus fluviatilis.
• 2.2.The osmotic pressure, sodium and chloride ion concentrations were measured in the haemocoelic fluid of Modiolus fluviatilis under similar conditions.
• 3.3.Free amino acids (measured as ninhydrin-positive substances) were determined in the muscle tissue of Modiolus.
• 4.4.It appears that these free amino acids are involved in the ability of the estuarine bivalve Modiolus fluviatilis to osmoregulate in a wide range of salinities.