Ion-dependent Viscosity of Holothurian Body Wall and its Implications for the Functional Morphology of Echinoderms

1982 ◽  
Vol 99 (1) ◽  
pp. 1-8
Author(s):  
JOHN P. EYLERS
Keyword(s):  
Sea Water ◽  
Divalent Cations ◽  
Constant Load ◽  
Distilled Water ◽  
Sodium Potassium ◽  
Monovalent Ions ◽  
Cross Links ◽  
Calcium And Magnesium ◽  
Dependent Viscosity ◽  
The Relationship

Dermis from the holothurian Thyone inermis was subjected to constant load and its rate of plastic deformation (creep) was used to calculate tissue viscosity. During these tests the material was bathed in distilled water, sea water, or solutions of sodium, potassium, calcium, and magnesium salts in various combinations. Distilled water caused a threefold increase in viscosity which was reversed by sea water. Sodium and potassium decreased viscosity, while calcium and magnesium in combination with sodium increased it. Ionic cross-links shielded by monovalent ions but facilitated by divalent cations are proposed to explain this behaviour, and the relationship between this and other anomalies of echinoderm connective tissue physiology is discussed.

scholarly journals THE EFFECT OF ELECTROLYTES ON THE CONTRACTILE ELEMENTS OF MUSCLE

1952 ◽  
Vol 35 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Emil Bozler
Keyword(s):  
Cardiac Muscle ◽  
Electrolyte Concentration ◽  
Divalent Cations ◽  
Muscular Contraction ◽  
Small Degree ◽  
Distilled Water ◽  
Rapid Rise ◽  
Polar Groups ◽  
Monovalent Ions ◽  
Water Tension

The effects of changes in electrolyte concentration on muscles which had been preserved in 50 per cent glycerol or washed in water were studied. The psoas preparation of Szent-Györgyi was generally used, but smooth and cardiac muscle gave the same results. If the preparations are immersed in 0.16 molar NaCl or KCl and if the electrolyte subsequently is washed out with distilled water, tension rises. This effect is not obtained if solutions of CaCl2 or MgCl2 are used, but it is restored by brief immersion in NaCl or KCl solutions. Changes in pH have no effect. It is concluded that divalent cations are bound more firmly than monovalent ions, but that divalent exchange with monovalent ions. After the application of ATP washing out electrolytes produces a much larger and more rapid rise in tension. This effect persists after ATP has been washed out and seems to be due to the removal of a substance which diminishes the dissociation of bound cations. Washing out electrolytes also causes a large increase in transparency and swelling. These effects are also enhanced by previous application of ATP and are abolished or diminished by divalent cations. The rise in tension and the swelling are explained as the result of an increase in the charge of the polar groups of the proteins. Because this mechanism produces only a small degree of shortening, it does not explain normal contraction, but it may be a part of this process. The significance of the phenomena described in relation to recent theories of the mechanism of muscular contraction is discussed. The observations show that increase in the charge of the contractile proteins causes contraction, not relaxation, as has been commonly assumed.

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.

scholarly journals THE BEHAVIOR OF ISOLATED HEARTS OF THE GRASSHOPPER, CHORTOPHAGA VIRIDIFASCIATA, AND THE MOTH, SAMIA WALKERI, IN SOLUTIONS WITH DIFFERENT CONCENTRATIONS OF SODIUM, POTASSIUM, CALCIUM, AND MAGNESIUM

1954 ◽  
Vol 38 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Mary C. Barsa
Keyword(s):  
Osmotic Pressure ◽  
Sodium Content ◽  
Heart Beat ◽  
Distilled Water ◽  
Normal Heart ◽  
Protein Nitrogen ◽  
Sodium Potassium ◽  
Inorganic Cations ◽  
Isolated Hearts ◽  
Calcium And Magnesium

1. The blood of Chortophaga viridifasciata was analyzed. The average concentrations of inorganic cations expressed as milligrams per cent are: sodium, 250.66; potassium, 13.52; calcium, 11.40; and magnesium, 51.15. The osmotic pressure of the blood at 0°C. is 10.7 atmospheres. Protein and non-protein nitrogen, expressed as milligrams per cent, are 253.4 and 140.0, respectively. 2. The blood of Samia walkeri has an osmotic pressure of 13.36 atmospheres at 0°C. Its protein nitrogen is 628.58, and its non-protein nitrogen, 441.20 milligrams per cent. 3. The effects of isotonic chloride solutions of sodium, potassium, calcium, and magnesium and of distilled water on the heart beat of these two species were determined. The heart of the grasshopper failed to beat in isotonic solutions of KCl, MgCl2, or in distilled water. For both insects, sodium was found to be the least toxic ion. In the case of the grasshopper, calcium ranks next in order. In the case of the moth, potassium ranks next after sodium and is followed by calcium and magnesium. 4. The ratio of sodium to potassium in milligrams per cent, necessary for maintaining the normal heart beat of Chortophaga viridifasciata is 3 to 1, but it may be increased to at least 34 to 1 without any appreciable effects. The ratio of potassium to calcium necessary for maintaining the normal heart beat of this insect is 1 to 1, and may be increased to as much as 3 to 1. 5. The ratio of sodium to potassium, in milligrams per cent, necessary for maintaining the normal heart beat of Samia walkeri was found to be equal to or to exceed 1 to 13.8. The sodium content may be increased so that the ratio of sodium to potassium is 34 to 1 without any toxic effects. The ratios of potassium to calcium required for normal heart beat in this insect may be 1 to 1, 2 to 1, or 3 to 1. 6. The hearts of the grasshoppers beat normally in isotonic solutions having an osmotic pressure of 10.7 atmospheres. They beat equally well in solutions having an osmotic pressure of 13.4 atmospheres. The hearts of the cynthia pupae beat normally in isotonic solutions having an osmotic pressure of 13.36 atmospheres. However, they also beat normally in solutions having an osmotic pressure of 10.02 atmospheres. Therefore, although the blood of the cynthia moth and of the grasshopper have different osmotic pressures, their hearts are tolerant to solutions having the same tonicity. Because of this, and since the ratios of potassium to calcium necessary for maintaining normal heart beats of both insects are the same, solutions favorable to the grasshopper may also be favorable to the cynthia moth.

Studies on the Growth of Phaeodactylum Tricornutum VI. the Relationship to Sodium, Potassium, Calcium and Magnesium

1970 ◽  
Vol 50 (2) ◽  
pp. 293-299 ◽  
Author(s):  
J. Hayward
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Ionic Composition ◽  
Sodium Potassium ◽  
Major Cations ◽  
Water Media ◽  
Salinity Levels ◽  
Half Strength ◽  
The Media ◽  
Calcium And Magnesium

The growth of certain unicellular marine algae has been shown to occur in culture solutions whose total ionic content and chemical composition departs markedly from that of natural sea water. In fact, some of these algae apparently grow more rapidly in half-strength sea water media than in a medium of salinity equal to 35‰. This ability, on the part of the algae, to grow at widely different salinities suggests that the algal cells are able to maintain an internal ionic composition despite wide variation in the external composition of the surrounding culture medium in which they are growing. Droop (1958) has shown that the major cations present in sea water can be varied within wide limits and it was decided to concentrate on the cations, sodium, potassium, calcium and magnesium. A series of analyses of Phaeodactylum tricornutum has been carried out to determine the concentrations of the four cations present in the cells and also to determine whether these concentrations vary during the growth of cells in culture over a period of time. In addition the analyses have been carried out on cells which have been grown at two different salinities, to compare internal cellular concentrations at different salinity levels of the media.

Trace Metal Uptake and Sodium Regulation in Gammarus Marinus From Metal Polluted Estuaries in England

1986 ◽  
Vol 66 (1) ◽  
pp. 83-92 ◽  
Author(s):  
David A. Wright
Keyword(s):  
Trace Elements ◽  
Metal Uptake ◽  
Sea Water ◽  
Major Ions ◽  
The Other ◽  
Regulatory Mechanisms ◽  
Sodium Potassium ◽  
Calcium And Magnesium ◽  
Sodium Regulation ◽  
Blood Pigment

The regulation of major ions in aquatic Crustacea has been extensively studied, and it is hardly surprising that ever-present ionic constituents of sea water such as sodium, potassium, chloride, calcium and magnesium have been incorporated into highly efficient regulatory mechanisms. On the other hand, we know little of the mechanisms governing the uptake and regulation of trace elements, despite the fact that metals such as zinc and copper may be important constituents of enzymes and blood pigment.

Osmotic and Ionic Regulation in the Isopod Crustacean Ligia Oceanica

1953 ◽  
Vol 30 (4) ◽  
pp. 567-574
Author(s):  
G. PARRY
Keyword(s):  
Adverse Effects ◽  
Osmotic Pressure ◽  
Sea Water ◽  
Freezing Point ◽  
Inorganic Ions ◽  
Mean Value ◽  
Distilled Water ◽  
Freezing Point Depression ◽  
Sodium Potassium ◽  
Subsequent Decrease

1. Osmotic pressure of the blood of Ligia oceanica, measured by the freezing-point depression, has a mean value of δ 2.15 ± 0.04° C. (≡3.58% NaCl on weight/ volume basis). 2. Osmotic pressure of Ligia blood is much higher than that of other terrestrial isopods: Oniscus sp. δ1.04° C.; Armadillidium sp. δ1.18° C.;Porcellio sp. δ1.30° C. or of the fresh-water Asellus sp. δ0.50° C. 3. The osmotic pressure of the blood increases during the process of moulting, but no subsequent decrease is observed in the 4 days following. 4. Animals kept at low humidities lose water. They may be desiccated without permanent adverse effects until δblood is 3.48° C. (≡ 5.8% NaCl). Recovery to a normal level takes about 24 hr. in moist conditions. 5. In well-aerated sea water between 50 and 100% concentration, animals survive without much alteration in δblood. Above and below this range δblood rises and falls. 6. In animals kept on filter-paper moistened with distilled water δblood may fall to 1.44° C. (≡2.4% NaCl) without permanent adverse effects. 7. Analyses of inorganic ions in the blood show that sodium, potassium and chloride are all higher in concentration than in sea water; calcium is much more concentrated; and magnesium and sulphate much reduced.

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.

scholarly journals The Inorganic Constitution of Molluscan Blood and Muscle

1947 ◽  
Vol 26 (4) ◽  
pp. 580-589 ◽  
Author(s):  
F. R. Hayes ◽  
D. Pelluet
Keyword(s):  
Inorganic Material ◽  
Sea Water ◽  
The Other ◽  
Sodium Potassium ◽  
Marine Biological Association ◽  
Calcium Magnesium ◽  
Calcium And Magnesium ◽  
Lower Chloride ◽  
Two Phases ◽  
Whole Muscle

Estimations of sodium, potassium, calcium, magnesium, chloride and sulphate have been made on the blood and muscle of marine molluscs and of the freshwater clam, Anodonta.On comparing marine blood with sea water it appears that the cephalopods show a regulatory power (i.e. difference between blood and sea water) with respect to all ions tested except sulphate. The gastropods have a regulatory power for calcium, magnesium and chloride; the pelecypods for calcium and magnesium.Calcium is always higher in blood than in sea water, while magnesium is lower. Chloride, where it differs, is lower.If muscle is considered as two phases, cells and intercellular blood space, then from whole muscle and blood analyses it is possible to calculate the spaces between the cells, which work out at 11 % for pelecypods and 18 % for the other two groups. Further calculation gives the constitution of the cells themselves, leading to the conclusion that, of the ions under consideration, only K is present in the Pelecypoda and Cephalopoda, while the Gastropoda may have some Ca and Mg as well as K.As expected the fresh-water clam contains little inorganic material. In relative proportions its blood is characterized by more calcium and less magnesium and chloride than that of marine forms. In muscle cells potassium dominates but other ions are present as well.This work was carried out at the Laboratory of the Marine Biological Association, Plymouth, in the summers of 1936 and 1937, and at the Oceanographic Institution, Woods Hole, in 1939. It is a pleasure to express our thanks to the Directors and Staffs of these establishments for accommodation,facilities and advice during the progress of the investigation.

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