Amino acid deprivation, effect

T. Repko, and E. J. Hoffman. 1963. The effect of amino acid deprivation on... 

Table n. Effect of Amino Acid Deprivation on Membrane Composition"... 

Although essential amino acids are requited by both host and tumor, deprivation of select essential amino acids for 2—3 weeks is tolerated by the host yet exerts a pronounced antiproliferative effect on the tumor. Thus, treatment of mice with indole-3-alkane-a-hydroxylase [63363-76-8] from Pseudomonas, which transforms L-tryptophan [73-22-3] to 3-indolylglycaldehyde, lowers the concentration of L-tryptophan in plasma, brain, and lungs, and inhibits the growth of a variety of tumors (32—34). 

What effect does deprivation of dietary pyridoxal phosphate have on the capacity to metabolize amino acids ... 

Flynn, K. J., and Al-Amoudi, O. A. (1988). Effects of nitrogen deprivation and darkness on composition of free amino acid pools in and on amino acid release from the diatom Phaeodactylum tricornutum Bohlin.J. Exp. Mar. Biol. Ecol. 119, 131—143. 

In a related vein, the subjective psychostimulant effects of amphetamine were attenuated following a 2-h pretreatment with a tyrosine- and phenylalanine-free amino acid mixture (118).These amino acids are biosynthetic precursors of the catecholamines, and deprivation would be expected to produce transient reductions in endogenous dopamine and norepinephrine. The authors concluded that tyrosine depletion attenuates the release of dopamine required for the psychostimulant effect. Interestingly, the pretreatment did not reduce the subjective appetite-suppressant (anorectic) effect of amphetamine. The study authors attributed this latter finding to a continued release of norepinephrine by amphetamine. Tyrosine depletion, however, would also attenuate norepinephrine biosynthesis and it may be more reasonable to conclude that the anorectic effect might be related to the often-overlooked ability of amphetamine to release neuronal serotonin. 

Severe deficiency of dietary protein produces a marked lowering of plasma albumin, and this is usually considered to occur as a result of depressed synthesis due to the deprivation of essential amino acids. A marked hypoalbuminemia in the rat and dog (F7) and in the cat (G24) has resulted from experimentally induced chronic choline deficiency. The effect was not reversed by a dietary supplement of methionine, but was reversed by choline supplementation. This situation bore no direct relation to the fatty... 

The basics of nonpharmacologic approaches should address issues of adequate nutrition, sleep, exercise, and stress reduction. Sleep deprivation, high stress, and deficiencies in dietary essential amino acids, fatty acids, vitamins, and minerals may exacerbate mood episodes and result in poorer outcomes. Another effective treatment is to combine medications with adjunctive psychoeduca-tional programs, supportive counseling, insight-oriented psychother-... 

In some other cases, the sole role of the metal seems to be to ensure the correct tertiary folding of the protein, similar in effect to the S—S bond. This folding often brings together two or three amino acid residues that are situated far from one another in the extended polypeptide chain, but which can form the active site when assembled in this way. An example is zinc in the alkaline phosphatase of E. coli when deprived of zinc, its circular-dichroism spectrum was radically changed by 6 M urea, as the native conformation gave way to a random coil (Trotman and Greenwood, 1971). For more about this enzyme see Section 11.0, under Zinc. 

Under conditions when the average rate of protein catabolism is increased, such as during insulin deprivation, amino acid limitation, or serum deprivation, inhibitors or lysosomotropic amines partially inhibit the enhanced protein degradation. However, effects on normal or basal protein catabolism are controversial. Some workers (122, 123)... 

VAN TENROOU, W.J.W., HENSHAW, E.C. and KLRSCH, C.A. Effects of deprival of glucose or individual amino acids on polyribosome distribution and rate of protein synthesis in cultured mammalian cells. Biochem. Biophys. Acta. (1972), 259. 

The bulk of clinical studies dealing with nutrient modulation of immune function have dealt with patients suffering from kwashiorkor or marasmus where protein deprivation plays a major role. These studies have pointed to the importance of protein quality as well as quantity in effectiveness indicating the importance of amino acid balance and certain specific amino acids. Recent experiments have concentrated on the use of animal models to define the role of individual essential amino acids in modulating the cell-mediated or... 

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