Absorption, Transportation, and Distribution

There appears to be no control of the absorption of dietary sodium, which essentially is totally absorbed, provided that glucose is available for transport processes. Sodium absorption takes place by several mechanisms, of which electroneutral cotransport subsystems account for about 20%, diffusion possibly for up to 50%, and other transport processes for the remainder. Sodium-glucose and sodium-amino acid cotransporters exist in the apical membranes of erythrocytes and mediate sodium uptake coupled to glucose or amino acid uptake. Thus, the absorption of glucose and some amino acids is dependent on sodium uptake. 

In the absence of glucose, infusion of saline via a nasogastric tube at high flow rates induces an osmotic diarrhea which is therapeutically useful in conditions such as cystic fibrosis and severe constipation. Physiological controls on whole-body sodium are mediated through the kidney, but each cell membrane contains the means to regulate intracellular sodium. Hypothalamic mecha- 

Women = 100%, Men = x%. Significance level of students t-test Fp = Significance level in simple factor multiple variance analysis G = Germany M = Mexico. 

The following systems are involved in the maintenance of the sodium balance  

It is important to realize that in the event of one system malfunctioning, or in the con- 

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A. Bjpmeboe, G-E. Bjpmboe, and C. A. Drevon Absorption, transport and distribution of vitamin E. Journal of Nutrition 120,233 (1990). 

Uptake, Absorption, Transport and Distribution, Metabolism and Elimination in Plants, Animals, and Humans... 

Absorption, Transportation, and Distribution Rubidium is very well absorbed from the alimentary tract of animals (Schafer and Forth 1983), with absorption in humans exceeding 60% in both sexes (Table 1.4-5). Rubidium resembles potassium in its pattern of absorption (channels). On the basis of studies with brush border membrane vesicles isolated from the jejuna of rabbits, potassium and rubidium apparently share a transport system. All plant and animal cells are apparently permeable to rubidium ions at rates comparable with those of potassium (Nielsen 1986). It seems that rubidium uses the potassium channels for entering the cell (Clay and Shlesinger 1983, Gallacher et al. 1984). All soft tissues of the body have rubidium concentrations that are high compared with trace elements, with a typical... 

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