Ionic regulation and Na+,K+-ATPase activity in gills and kidney of the Antarctic aglomerular cod icefish exposed to dilute sea water

2001 ◽  
Vol 59 (2) ◽  
pp. 463-468 ◽  
Author(s):  
S. Romao ◽  
C. A. Freire ◽  
E. Fanta
Keyword(s):  
Atpase Activity ◽  
Sea Water ◽  
Ionic Regulation ◽  
The Antarctic

Metabolic importance of Na+/K+-ATPase activity during sea urchin development.

1997 ◽  
Vol 200 (22) ◽  
pp. 2881-2892 ◽  
Author(s):  
P Leong ◽  
D Manahan
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Sea Urchin ◽  
Sodium Pump ◽  
Sea Water ◽  
Strongylocentrotus Purpuratus ◽  
Lytechinus Pictus ◽  
Stimulation Of

Early stages of animal development have high mass-specific rates of metabolism. The biochemical processes that establish metabolic rate and how these processes change during development are not understood. In this study, changes in Na+/K+-ATPase activity (the sodium pump) and rate of oxygen consumption were measured during embryonic and early larval development for two species of sea urchin, Strongylocentrotus purpuratus and Lytechinus pictus. Total (in vitro) Na+/K+-ATPase activity increased during development and could potentially account for up to 77 % of larval oxygen consumption in Strongylocentrotus purpuratus (pluteus stage) and 80 % in Lytechinus pictus (prism stage). The critical issue was addressed of what percentage of total enzyme activity is physiologically active in living embryos and larvae and thus what percentage of metabolism is established by the activity of the sodium pump during development. Early developmental stages of sea urchins are ideal for understanding the in vivo metabolic importance of Na+/K+-ATPase because of their small size and high permeability to radioactive tracers (86Rb+) added to sea water. A comparison of total and in vivo Na+/K+-ATPase activities revealed that approximately half of the total activity was utilized in vivo. The remainder represented a functionally active reserve that was subject to regulation, as verified by stimulation of in vivo Na+/K+-ATPase activity in the presence of the ionophore monensin. In the presence of monensin, in vivo Na+/K+-ATPase activities in embryos of S. purpuratus increased to 94 % of the maximum enzyme activity measured in vitro. Stimulation of in vivo Na+/K+-ATPase activity was also observed in the presence of dissolved alanine, presumably due to the requirement to remove the additional intracellular Na+ that was cotransported with alanine from sea water. The metabolic cost of maintaining the ionic balance was found to be high, with this process alone accounting for 40 % of the metabolic rate of sea urchin larvae (based on the measured fraction of total Na+/K+-ATPase that is physiologically active in larvae of S. purpuratus). Ontogenetic changes in pump activity and environmentally induced regulation of reserve Na+/K+-ATPase activity are important factors that determine a major proportion of the metabolic costs of sea urchin development.

Ionic Regulation of the Baltic and Fresh-Water Races of the Isopod Mesidotea (Saduria) Entomon (L.)

1968 ◽  
Vol 48 (1) ◽  
pp. 141-158 ◽  
Author(s):  
P. C. CROGHAN ◽  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
Relative Volume ◽  
Ice Age ◽  
Ionic Regulation ◽  
Sodium Influx ◽  
Active Uptake ◽  
Concentrated Solution ◽  
The Baltic

1. The isopod Mesidotea entomon has colonized the Baltic and certain Swedish lakes since the end of the last Ice Age. 2. The ionic regulation of Baltic animals and fresh-water animals (L. Mälaren) has been compared. 3. It has been possible to adapt Baltic animals to very dilute media, but 5% Askö sea water (5.5 mM/l. Na) appears to be the limit of adaptation. The haemolymph sodium concentration of Baltic animals from the very dilute media was considerably lowered. 4. The haemolymph sodium concentration in Mälaren animals is high (250 mM/l. Na) and comparable with that in Baltic animals in much more concentrated solution. The haemolymph ionic ratios of the Baltic and freshwater animals are similar. The Cl:Na ratio rises slightly in the more concentrated haemolymph samples. 5. From the concentration of ions in the haemolymph and in the total body water, the relative volume of the haemolymph was calculated. Mälaren animals appear to have a much larger haemolymph volume. 6. The permeability of the animals was determined from the rate of loss of sodium into de-ionized water. The permeability of the Mälaren animals is considerably reduced compared to the Baltic animals. Permeability is not related to the medium to which the animals had been adapted. 7. The sodium influx was determined using 22Na. The rate of active uptake was calculated from this. The maximal rate of active uptake was similar in Baltic and Mälaren animals. The sodium concentration of the medium at which active uptake was half maximum (KM) was considerably lower in Malaren animals than in Baltic animals. 8. The evolution of Mesidotea as a fresh-water animal is interpreted as a result of a reduction in permeability of the external surfaces to NaCl and an increase in the affinity of the active transport mechanism enabling the animal to maintain the haemolymph NaCl concentration in a steady state in fresh water.

3. On the Distribution of Temperature in the Antarctic Ocean

1888 ◽  
Vol 14 ◽  
pp. 147-149
Author(s):  
J. Y. Buchanan
Keyword(s):  
General Result ◽  
Cold Water ◽  
Sea Water ◽  
Antarctic Ocean ◽  
Higher Temperature ◽  
The Antarctic ◽  
Ice Pack ◽  
Overlying Strata

AbstractIn the regions of the Antarctic Ocean where icebergs are numerous, and where in winter the sea-water freezes, the distribution of temperature in the deeper layers of water is peculiar. The facts are detailed in the Challenger Narrative (vol. i.). The general result of her observations went to show that, from the edge of the ice-pack, a wedge of cold water stretches northwards for more than 12° of latitude, underlying and overlying strata at a higher temperature than itself (p. 418).

scholarly journals REVERSIBLE CARDIAC ARREST INDUCED BY STARTLING STIMULI IN THE ANTARCTIC FISH Notothenia neglecta

1998 ◽  
Vol 3 (1) ◽  
Author(s):  
KATSUMASA HOSHINO ◽  
PEDRO HELIO LUCCHIARI ◽  
METRY BACILA
Keyword(s):  
Heart Rate ◽  
Cardiac Arrest ◽  
Common Property ◽  
Sea Water ◽  
Antarctic Fish ◽  
Experimental Chamber ◽  
Short Delay ◽  
Common Response ◽  
The Antarctic ◽  
Temporary Inhibition

Estímulos de alarme induzem inibição temporária dos batimentos cardíacos em muitos animais. Como essa proprieade, denominada parada (arrest) cardíaca reversível não vem sendo estudada sistematicamente em peixes, os presente trabalho investigou a sua ocorrência em peixes antárticos que evoluíram independentemente de outros grupos de teleósteos. Alterações do ritmo cardíaco em resposta a diferentes estímulos foram monitoradas por registro eletrocardiográfico em 15 espécimes de Notothenia neglecta (400-700 g) mantidas em uma câmara experimental com água do mar aerada e temperatura controlada. Vibrações repentinas da câmara, a aproximação do observador e outros estímulos de alerta provocavam no animal paradas cardíacas algumas vezes por um ou mais batimentos, mas a resposta mais comum era somente de uma parada curta do batimento cardíaco após estímulo. Aumento da temperatura até 11ºC eleva o ritmo (rate) cardíaco sem abolir a resposta contudo. Hipóxia moderada facilita a parada cardíaca. Inibição cardíaca pronunciada com algum batimento isolado foi observada quando os animais eram manuseados ou quando a água da câmara era removida. Administração de atropina (1 mg/kg) bloqueia a parada cardíaca induzida por tais procedimentos. Conclui-se, então, que a parada cardíaca reversível é provavelmente uma propriedade comum de muitos peixes que se desenvolveu antes da sua adaptação ao ambiente antártico. Abstract Startling stimuli induce temporary inhibition of heart beats in many animals. Since such property, named reversible cardiac arrest, has not been systematically studied in fishes, the present work investigated its occurrence in an Antarctic fish that evolved independently from other teleost groups. Heart rate changes in response to different stimuli were monitored by conventional electrocardiographic recording in 15 Notothenia neglecta (400-700 grams), maintained in an experimental chamber with aerated sea water and controlled temperature. Sudden vibration of the chamber, observer approximation and other alerting stimuli evoked cardiac arrest sometimes for one or more beats, but the most common response was only a short delay of the beat after the stimulus. Increase in temperature up to 11ºC raised heart rate but did not abolish the response. Moderate hypoxia facilitated cardiac arrest. Pronounced cardiac inhibition with some isolated beats was observed when the animals were handled or when the water of the chamber was removed. Atropine (1mg/kg) administration blocked the cardiac arrest induced by such procedures. It is concluded that reversible cardiac arrest is probably a common property of many fishes and developed before the adaptation to the Antarctic environment.

Angiotensin II receptors in the gill of sea water- and freshwater-adapted eel

1997 ◽  
Vol 18 (1) ◽  
pp. 67-76 ◽  
Author(s):  
S Marsigliante ◽  
A Muscella ◽  
G P Vinson ◽  
C Storelli
Keyword(s):  
Image Analysis ◽  
Angiotensin Ii ◽  
Atpase Activity ◽  
Sea Water ◽  
Anguilla Anguilla ◽  
Chloride Cell ◽  
Chloride Cells ◽  
Angiotensin Ii Receptors ◽  
Receptor Subtypes ◽  
Ang Ii

ABSTRACT Immunocytochemistry of paraffin-embedded and cryostat sections of eel (Anguilla anguilla) gill showed that angiotensin II receptors (Ang II-R) were present in chloride cells, uniformly distributed in the cytoplasm and on surface membranes. Computerised image analysis of these preparations showed that gills from sea water (SW)-adapted animals had a significantly (3-fold) higher Ang II-R concentration compared with freshwater (FW)-adapted eel gills. Isoelectric focusing gel electrophoresis revealed two Ang II-R isoforms with pI 6·5 and 6·6 that were differentially modulated by environmental salinity: they were equally abundant in SW while in FW the pI 6·6/pI 6·5 ratio was 1·66. Using catalytic cytochemistry with image analysis, gill chloride cell membrane Na+/K+ATPase activity was shown to increase 4-fold in response to SW adaptation. Additionally, perfusion of gills for 30 min with 0·1, 10 or with 100 nM Ang II provoked a dose-dependent increment in Na+/K+ATPase activity in FW, and a biphasic response in SW gills in which activity was significantly increased at low Ang II concentrations but was reduced to basal values at 100 nM. The data suggest that adaptation to sea water significantly increases Ang II-R concentration in the chloride cell and, together with the effects of Ang II on Na+/K+ATPase activity, suggest a role for this hormone in gill NaCl retention. The different responses of Na+/K+ATPase to Ang II stimulation in FW and SW may be attributed to the presence of two receptor subtypes that are differently modulated by salinity and that have opposing effects on Na+/K+ATPase.

scholarly journals Monitoring of atmospheric aerosol particles on the Antarctic Peninsula

1998 ◽  
Vol 27 ◽  
pp. 560-564 ◽  
Author(s):  
Alexandre Correia ◽  
Paulo Artaxo ◽  
Willy Maenhaut
Keyword(s):  
Atmospheric Aerosol ◽  
Sea Water ◽  
Seasonal Pattern ◽  
Aerosol Particles ◽  
Sea Salt ◽  
Water Composition ◽  
Atmospheric Aerosol Particles ◽  
Clear Seasonal Pattern ◽  
Fine Mode ◽  
The Antarctic

Atmospheric aerosol particles have been sampled since 1985 at the Brazilian Antarctic station, Comandante Ferraz (62°05' S, 58°23 5'W) Stacked niter units were used to collect particles with an aerodynamic diameter of less than 10μm. The elemental concentration was measured by particle-induced X-ray emission, yielding data for 23 elements: Na, Mg, Al, Si, P, S, Cl, K, Ca, K, V, Cr, Mn, Fe, Ni, Cu, Zn Sc, Br Kb, SrZr and Pb. The detection limit was typically near 5 ng m −3 for elements with atomic number (z) less than 20, and Oingm for 21 < z <.30. Principal-factor and cluster analyses identified four sources for the Antarctic aerosol: fine and coarse sea salt, soil dust and sulphates. The fine-mode non-sea-salt sulphate concentration showed a clear seasonal pattern accompanying the biological cycle of algae, with minimum during winter. Some elements, such as Ni and Pb, showed very high enriched concentrations relative to the bulk sea-water composition. This indicates the existence of sources of regional or long-range transported pollution.

Ionic Regulation Ability in Rutilus frisii kutum Fingerlings During Sea Water Adaptation

2011 ◽  
Vol 6 (7) ◽  
pp. 728-739
Author(s):  
S.A. Hosseini ◽  
C.R. Saad ◽  
M.S. Bourani ◽  
H.M. Daud ◽  
S.A. Harmin ◽  
...  
Keyword(s):  
Sea Water ◽  
Ionic Regulation ◽  
Rutilus Frisii Kutum ◽  
Sea Water Adaptation
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