Amino acid cholesterol levels

Raja, P. K. and Jarowski, C. I., Utility of fasting essential amino acid plasma levels in formulation of nutritionally adequate diets. IV. Lowering of human plasma cholesterol and triglyceride levels by lysine and tryptophan supplementation, J. Pharm. Sci., 64, 691, 1975. 

Table V. Serum Cholesterol Levels in Rabbits fed Casein, Soy Protein, Their Hydrolysates and Their Amino Acid Mixtures...

Heterozygous carriers of functionally relevant mutations usually present with HDL cholesterol levels that are frequently below the fifth percentile. As would be expected, apoA-I levels are also frequently below the fifth percentile (i.e., < 1.05 g/1 and < 1.1 g/1 in Caucasian men and women, respectively). In most cases, heterozygous carriers of apoA-I variants do not present with specific clinical symptoms. An important exception are some structural apoA-I variants with amino acid substitutions in the amino terminus, which have been detected in patients with familial amyloidosis of the liver, the intestine, the kidney, the heart, peripheral nerves, and in the skin. In addition, some apoA-I variants like apoA-I L178P or L159P have been associated with increased risk of premature coronary heart disease or enhanced progression of carotid intima media thickness, whereas others did not show this association, or were even claimed to have reduced cardiovascular risk and advocated as possible agents for the treatment or prevention of atherosclerosis (notably apoA-I R173CMiiano) [22,43,53]. 

The major biochemical changes observed are a striking depletion of ATP, impaired protein synthesis, defective incorporation of amino acids, and the appearance of RNA and proteins containing the ethyl rather than the methyl group. The plasma levels of triglycerides, cholesterol, lipoprotein, and phospholipid are all decreased. 

The plasma lipoproteins contain eight major apoproteins, the structure and function of which have recently been reviewed (5). Briefly, the primary amino acid sequence is known for five of these apoproteins. ApoB, a highly hydrophobic protein, is found in chylomicrons, VLDL and LDL. It is the major polypeptide in LDL and has been shown to be responsible, in part, for the recognition of LDL by its receptor in cultured human fibroblasts (7,10). The major polypeptides of HDL are apoA-I and apoA-II apoA-l activates lecithin cholesterol acyl transferase. In addition, studies on the cellular level suggest that apoA-I may regulate the content of the lipids in the cell membrane (8). 

Administration of inorganic trivalent chromium compounds or extracts of brewers yeast resulted in decreased blood glucose levels and cholesterol levels and regression of atherosclerotic plaques (Pi-Sunyer and Offenbacher 1984). Improved insulin sensitivity also resulted in an increased incorporation of amino acids into proteins and cell transport of amino acid in rats receiving supplemental chromium (Roginski and Mertz 1969). 

Forsythe, W.A., Miller, E.R., Hill, G.M., Romsos, D.R., and Simpson, R.C. 1980. Effects of dietary protein and fat sources on plasma cholesterol parameters, LCAT activity and amino acid levels and on tissue lipid content of growing pigs. J. Nutr. 110(12), 2467-2479. 

Sugiyama, K., Ohkawa, S., and Muramatsu, K. 1986. Relationship between amino acid composition of diet and plasma cholesterol level in growing rats fed a high cholesterol diet. J. Nutri. Sci. Vit.,32,413 123. 

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