Isoleucine starvation

The mechanism of action of isoleucine starvation is not clear but it is not simply a general deficiency of amino acids as e.g. leucine starvation causes a far more drastic inhibition of cell growth without any synchronising action (Everhart, 1972 Tobey, 1973). Rather it may indicate some subdivision of G1-phase, and the presence of isoleucine appears to be important for the action of IGF ( 11.6) (Scher et al., 1977). 

Dressaire, C., Redon, E., Gitton, C., et al. (2011) Investigation of the adaptation of Lactococcus lactis to isoleucine starvation integrating dynamic transcriptomc and proteome information. Microb Cell Fact 10 (Suppl 1), S18. 

Amino acid catabohsm is particularly important dining starvation. Because of the mass of muscle, amino acid catabohsm is particularly important in this tissue which, in starvation, supplies the liver with most of its gluconeogenic precursors (see also Fig. 13-11). Amino acids resulting from proteolysis during starvation are interconverted in the muscle so that 60% of the amino acid mass that leaves the muscle is either glutamine or alanine. The branched-chain amino acids valine, leucine, and isoleucine, which are aU essential amino acids, are deaminated in muscle by a specific aminotransferase, and the corresponding 2-oxoacids are transported to the liver for further metabohsm via branched-chain 2-oxoacid dehydrogenase (BCOADH). The aminotransferase is inactive in the hver, and this ensures that the peripheral tissues are supphed with valine, leucine, and isoleucine. 

Stanbury et al., 1983) to see whether there is a disease associated with those ammo acids If an individual ammo acid value is less than 1 5 X normal or the patient data involves many amino acid abnormalities, it is a good idea to look at patterns. For instance, a mildly increased plasma Gly along with decreased levels of Val, Leu, and/or isoleucine usually indicates starvation in the patient Increases of Tyr and Met together may indicate hereditary tyrosinemia An elevation of seven or eight amino acids may indi-... 

Isoleucine, Leu, and Val are elevated in maple syrup unne disease and decreased in starvation (see above). 

Studies on liver nucleoli after starvation have shown that the nucleoli are reduced to one-half of their size 24 hours after the onset of starvation. Two days later, they have practically vanished from the nucleus. They reappear, however, within three hours after food is given. In contrast, rat liver nucleoli enlarge after administration of a diet free of protein or deficient in any one of the essential amino acids (lysine, threonine, isoleucine, methionine, tryptophan, valine) except phenylalanine, leucine, and histidine. 

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