The Absorption of Sodium Ions by the Crayfish Astacus Pallipes Lereboullet

1960 ◽  
Vol 37 (3) ◽  
pp. 548-556
Author(s):  
J. SHAW
Keyword(s):  
Loss Rate ◽  
External Solution ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Ammonium Ions ◽  
External Concentration ◽  
Sodium Influx ◽  
Hydrogen Ion Concentration ◽  
Sodium Loss ◽  
Ammonium Compounds

1. The effect of various cations in the external solution on the sodium influx in the crayfish, Astacus pallipes, has been studied. 2. Potassium in concentrations up to 4 mM./l. has no significant effect on the sodium influx from 0.05 mM./l. NaCl solutions. 3. Calcium has no effect on the influx in concentrations up to 1 mM./l. At higher concentrations the influx may be reduced in some cases. 4. Magnesium generally increases the influx by about 30%. The effect is not related to the external concentration. 5. Ammonium ions reduce sodium influx. With an ammonium/sodium concentraton ratio of 20:1 the influx is reduced to about 20% of normal. Ammonium ions do not affect the sodium loss rate. 6. Simple substituted ammonium compounds have little effect on the influx. 7. The external hydrogen ion concentration reduces sodium influx if the pH is below 6. At pH 4 the influx is reduced to 20-30% of normal. A low pH does not decrease the rate of sodium loss. 8. The nature of the specific inhibition of sodium influx by ammonium ions is discussed. It is suggested that the ammonium ions interfere with a normal sodium ammonium exchange mechanism.

Studies on Sodium Balance in Gammarus Duebeni Lilljeborg and G. Pulex Pulex (L.)

1961 ◽  
Vol 38 (1) ◽  
pp. 1-15
Author(s):  
J. SHAW ◽  
D. W. SUTCLIFFE
Keyword(s):  
Loss Rate ◽  
Sea Water ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Nacl Solution ◽  
Uptake Mechanism ◽  
External Concentration ◽  
Sodium Influx ◽  
Low Concentrations ◽  
Sodium Loss

1. The mechanisms of sodium balance in Gammarus duebeni and G. pulex, adapted to various external concentrations, were compared. 2. G. duebeni could be adapted to live in 1 mm/l. NaCl solution and, in some cases, to concentrations down to 0.2 mM/l. G. pulex could survive in concentrations as low as 0.06 mM/l. 3. The sodium loss rate in G. duebeni adapted to 2% sea water was much higher than in G. pulex but was reduced to about the same level when the animals were adapted to low external concentrations. 4. In both species there was a non-linear relationship between sodium influx and the external sodium concentration. In G. duebeni the uptake mechanism was saturated at an external concentration of about 10 mM/l., whereas in G. pulex saturation was reached at a much lower concentration. The maximum rate of uptake was greater in G. duebeni than in G. pulex. 5. In both species adaptation to low concentrations involved a small increase in the sodium influx and a reduction in the loss rate. 6. The most important factor in the superiority of G. pulex over G. duebeni in surviving at low external concentrations is the high affinity for sodium displayed by the uptake mechanism in G. pulex.

STUDIES ON THE PRESERVATION OF BLOOD: VI. THE INFLUENCE OF ADENOSINE AND INOSINE ON THE METABOLISM OF THE ERYTHROCYTE

1958 ◽  
Vol 36 (12) ◽  
pp. 1269-1276 ◽  
Author(s):  
David Rubinstein ◽  
Shelby Kashket ◽  
Orville F. Denstedt
Keyword(s):  
Lactic Acid ◽  
Organic Phosphate ◽  
Red Cells ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Phosphate Esters ◽  
Ammonium Ions ◽  
Hydrogen Ion Concentration ◽  
Full Effect ◽  
Citrate Dextrose

Inosine is as effective as adenosine in maintaining the organic phosphate esters in the erythrocytes during storage in the citrate–dextrose preservative medium. Adenosine undergoes deamination in the presence of erythrocytes with liberation of ammonia. The ammonia tends to counteract the increase in the hydrogen ion concentration caused by the glycolytic production of lactic acid. By maintaining the hydrogen ion concentration within the range favorable to the activity of hexokinase, adenosine tends to maintain the utilization of glucose in the preserved red cells. Inosine, on the contrary, does not resist the increase in hydrogen ion concentration of the cells during storage, hence the utilization of glucose rapidly becomes impaired and supplanted by the utilization of ribose derived from the nucleoside. The utilization of ribose remains practically unaffected by the increase in hydrogen ion concentration to pH 6.1. Ammonium ions stimulate the utilization of glucose by erythrocytes but in degree not sufficient to account for the full effect of adenosine.

STUDIES ON THE PRESERVATION OF BLOOD: VI. THE INFLUENCE OF ADENOSINE AND INOSINE ON THE METABOLISM OF THE ERYTHROCYTE

1958 ◽  
Vol 36 (1) ◽  
pp. 1269-1276 ◽  
Author(s):  
David Rubinstein ◽  
Shelby Kashket ◽  
Orville F. Denstedt
Keyword(s):  
Lactic Acid ◽  
Organic Phosphate ◽  
Red Cells ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Phosphate Esters ◽  
Ammonium Ions ◽  
Hydrogen Ion Concentration ◽  
Full Effect ◽  
Citrate Dextrose

Inosine is as effective as adenosine in maintaining the organic phosphate esters in the erythrocytes during storage in the citrate–dextrose preservative medium. Adenosine undergoes deamination in the presence of erythrocytes with liberation of ammonia. The ammonia tends to counteract the increase in the hydrogen ion concentration caused by the glycolytic production of lactic acid. By maintaining the hydrogen ion concentration within the range favorable to the activity of hexokinase, adenosine tends to maintain the utilization of glucose in the preserved red cells. Inosine, on the contrary, does not resist the increase in hydrogen ion concentration of the cells during storage, hence the utilization of glucose rapidly becomes impaired and supplanted by the utilization of ribose derived from the nucleoside. The utilization of ribose remains practically unaffected by the increase in hydrogen ion concentration to pH 6.1. Ammonium ions stimulate the utilization of glucose by erythrocytes but in degree not sufficient to account for the full effect of adenosine.

The Sodium Balance Mechanism in the Fresh-Water Amphipod, Gammarus Lagustris Sars

1967 ◽  
Vol 46 (3) ◽  
pp. 519-528
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sodium Concentration ◽  
The Body ◽  
Sodium Balance ◽  
External Concentration ◽  
Sodium Influx ◽  
Influx Rate ◽  
Sodium Loss ◽  
Balance Mechanism

1. The sodium balance mechanism of Gammarus lacustris in fresh water is virtually identical with that found in G. pulex. 2. The sodium transporting system at the body surface has a very high affinity for sodium ions. The system is half-saturated at an external concentration of about 0.14 mM/l. and fully saturated at about 1 mM/l. sodium. 3. The lowest external concentration at which sodium balance was maintained was 0.06 mM/l. 4. Both the total sodium loss rate and the sodium influx rate remained approximately constant in animals acclimatized to the range of external concentrations from 2 to 0.3 mM/l. NaCl. At lower concentrations the loss rate was reduced and the influx increased by a factor of about 1.5. 5. Changes in the sodium influx and loss rates are very closely linked together, and it is shown how these changes are related to the external sodium concentration.

scholarly journals THE EFFECT OF HYDROGEN ION CONCENTRATION ON THE LIQUEFACTION OF GELATIN

1919 ◽  
Vol 38 (1) ◽  
pp. 179-190
Author(s):  
Harrison E. Patten ◽  
Alfred J. Johnson
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration
Sign in / Sign up

Export Citation Format

Share Document