Interorgan relationship

Within the liver, elimination of ammonia occurs via urea synthesis (Chapter 17). Since urea is uncharged, it does not disturb the acid-base balance. Many interorgan relationships in protein and nitrogen homeostasis arose because of the role that the liver plays in excess nitrogen excretion. 

Uptake and Intracellular Consumption of Amino Acids Branched-chain Amino Acids Interorgan Relationship Summary... 

Three major factors are considered as important in determining the supply of tryptophan to the brain leading to serotonin synthesis (1) the extent of binding of tryptophan to serum albumin, which influences the pool of free (unbound) tryptophan that interacts with the amino acid carrier mechanism located at the blood-brain barrier, (2) the plasma tryptophan concentrations, and (3) the plasma concentration of other large neutral amino acids (LNAA), which compete with tryptophan for uptake into brain. Each factor can be influenced by the nutritional or hormonal status of the host and also by interorgan relationships in the metabolism of amino acids. 

In starvation, glucose utilization is abnormally low because of inadequate glucose supplies. In diabetes mellitus, glucose utilization is similarly low, but it is low because the hormonal stimulus to glucose utilization—namely, insulm—is defective. As a result, glucose is present in excessive amounts in the blood, but in deficient amounts in the cells of peripheral tissues. The consequences of insulin deficiency are comparable to those of starvation in revealing important aspects of interorgan metabolic relationships. 

As noted earlier, plasma Pb, although the more precise and meaningful toxicokinetic measure for interorgan Pb distribution and eventual dose—response relationships, has a myriad of analytical problems associated with its measurement (Mushak, 1998 U.S. EPA, 2006). For example, plasma lead content even in high exposures is quite low, so that contaminating Pb because of external contamination or Pb passage from hemolyzed cells to... 

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