scholarly journals Primary active sodium transport, oxygen consumption, and ATP: Coupling and regulation

1986 ◽  
Vol 29 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Lazaro J. Mandel
Keyword(s):  
Oxygen Consumption ◽  
Sodium Transport ◽  
Active Sodium ◽  
Active Sodium Transport

scholarly journals Nonequilibrium Thermodynamic Analysis of the Coupling between Active Sodium Transport and Oxygen Consumption

1974 ◽  
Vol 64 (3) ◽  
pp. 372-391 ◽  
Author(s):  
G. Danisi ◽  
F. Lacaz Vieira
Keyword(s):  
Oxygen Consumption ◽  
Sodium Transport ◽  
Chemical Potential ◽  
Nonequilibrium Thermodynamic ◽  
Potential Difference ◽  
Stoichiometric Ratio ◽  
Active Sodium ◽  
Na Transport ◽  
Chemical Potential Difference ◽  
Active Sodium Transport

Sodium transport and oxygen consumption have been simultaneously studied in the short-circuited toad skin. A constant stoichiometric ratio was observed in each skin under control condition (NaCl-Ringer's solution bathing both sides of the skin) and after block of sodium transport by ouabain. During alterations of sodium transport by removal and addition of K to the internal solution the stoichiometric ratio is constant although having a value higher than that observed in other untreated skins. The coupling between active sodium transport and oxygen consumption was studied after a theoretical nonequilibrium thermodynamic model. Studies were made of the influence of Na chemical potential difference across the skin on the rates of Na transport and oxygen consumption. A linear relationship was observed between the rates of Na transport and oxygen consumption and the Na chemical potential difference. Assuming the Onsager relationship to be valid, the three phenomenological coefficients which describe the system were evaluated. Transient increases in the rate of sodium transport and oxygen consumption were observed after a transitory block of sodium transport by removal of Na from the external solution. Cyanide blocks completely the rate of oxygen consumption in less than 2 min and the short-circuit current measured after that time decays exponentially with time, suggesting a depletion of ATP from a single compartment.

Micropuncture study of composition of proximal and distal tubular fluid in rat kidney

1963 ◽  
Vol 204 (4) ◽  
pp. 527-531 ◽  
Author(s):  
Karl J. Ullrich ◽  
Bodil Schmidt-Nielsen ◽  
Roberta O'Dell ◽  
Gundula Pehling ◽  
Carl W. Gottschalk ◽  
...  
Keyword(s):  
Sodium Transport ◽  
Rat Kidney ◽  
Active Sodium ◽  
Osmotic Diuresis ◽  
Active Sodium Transport ◽  
Anesthetized Rats ◽  
Micropuncture Study

Fluid was collected by micropuncture from proximal and distal convolutions of anesthetized rats and analyzed for inulin, sodium, urea, and total osmotically active solute. The proximal fluid/plasma (F/P) sodium ratio was not significantly different from unity in antidiuretic animals, but was as low as 0.78 during mannitol diuresis. The distal F/P sodium ratio averaged 0.62 in antidiuresis, and 0.24 during osmotic diuresis. The data are interpreted to indicate active sodium transport by both proximal and distal convolutions. The F/P ratios for inulin, urea, and total osmotically active solute are in general agreement with previous studies.

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