7-Amino butyric acid, metabolism

Apart from glutamate, asdocytes also uptake neurodans-mitters like gamma amino butyric acid (GABA), aspartate, taurine, [3-alanine, serotonin, and catecholamines. The fate of all these neurodansmitters is to be metabolized within asdocytes. 

Glutamate in the brain and central nervous system can be converted to gamma amino butyric acid (GABA), which is catalyzed by glutamate decarboxylase. GABA is a neurotransmitter inhibitor compound that can be metabolized by transamination followed by oxidation. 

Glutamate is a central amino acid in general amino-acid metabolism. It plays a major role in transamination, ammonia production, formation of ornithine, proline, glutamine, and g-amino butyric acid (GABA). 

In addition to the synthesis of organic acids, many LAB can also produce other interesting metabolites such as antibacterial compounds (e.g., bacteriocins) [7], aroma compounds (diacetyl, acetoin, etc.), vitamins, exopolysaccharides (EPS), low-calorie sugars (e.g., mannitol), short-chain fatty acids, and y-amino butyric acid (GABA) [4,8]. Owing to this metabolic versatihty, these bacteria can be used as microbial cell factories in the production of chemicals, pharmaceuticals, or other industrially relevant products [1, 9]. 

Rassin D K., Sturman J A, and Gaull G E, (1981) Sulfur ammo acid metabolism m the developing rhesus monkey brain. Subcellular studies of taurine, cysteinesulfmic acid decarboxylase, 7-amino-butyric acid, and glutamic add decarboxylase, / Neurochem 37, 740-748... 

Although it is possible to describe the clinicopatho-logical manifestations of pyridoxine deficiency and the metabolic role of pyridoxal phosphate, each pathological alteration cannot be explained by a specific metabolic alteration. Deficiency of a vitamin involved in several steps of the intermediary metabolism of amino acids is bound to be associated with severe clinicopath-ological changes, but the specific metabolic alterations responsible for the anemia and convulsions in pyridoxine deficiency have not been identified. y-Amino butyric acid, cystathione, sphingosine, and 5-hydroxy-tryptamine are compounds abundant in the brain. Pyridoxal phosphate is involved in their metabolic formation. Is there any correlation between the role of pyridoxal phosphate in the metabolism of these compounds and the development of convulsions and ataxia in pyridoxine deficiency Is the role of pyridoxine phosphate in the intermediary metabolism of sulfur amino acid related to the development of seborrheic dermatitis ... 

When injected to intact or ovariectomized rats or rabbits, estrogens stimulate the uptake of a-aminoiso-butyric acid, and the free amino acid levels in the uterus are increased. Similarly, the addition of diethylstilbestrol or estradiol disulfate to an Ehrlich ascites cell in vitro stimulates the amino acid uptake by the cells. These findings are interpreted by postulating that the hormones affect amino acid transport. The hormone could, however, stimulate the penetration of the amino acid by affecting the usage of amino acids through metabolic pathways rather than by directly affecting the transport mechanism. 

Carnitine, L-3-hydroxy-4-(trimethylammonium)butyrate, is a water-soluble, tri-methylammonium derivative of y-amino-jS-hydroxybutyric acid, which is formed from trimethyllysine via y-butyrobetaine [40]. About 75% of carnitine is obtained from dietary intake of meat, fish, and dairy products containing proteins with trimethyllysine residues. Under normal conditions, endogenous synthesis from lysine and methionine plays a minor role, but can be stimulated by a diet low in carnitine. Carnitine is not further metabolized and is excreted in urine and bile as free carnitine or as conjugated carnitine esters [1, 41, 42]. Adequate intracellular levels of carnitine are therefore maintained by mechanisms that modulate dietary intake, endogenous synthesis, reabsorption, and cellular uptake. 

Fig. 1.8 Asaccharolytic fermentation produces ammonia and short-chain fatty acids. This group of fermentations by oral bacteria utilizes proteins, which are converted to peptides and amino acids. The free amino acids are then deaminated to ammonia in a reaction that converts nicotinamide adenine dinucleotide (NAD) to NADH. For example, alanine is converted to pyruvate and ammonia. The pyruvate is reduced to lactate, and ammonium lactate is excreted into the environment. Unlike lactate from glucose, ammonium lactate is a neutral salt. The common end products in from plaque are ammonium acetate, ammonium propionate, and ammonium butyrate, ammonium salts of short chain fatty acids. For example, glycine is reduced to acetate and ammonia. Cysteine is reduced to propionate, hydrogen sulfide, and ammonia alanine to propionate, water, and ammonia and aspartate to propionate, carbon dioxide, and ammonia. Threonine is reduced to butyrate, water, and ammonia and glutamate is reduced to butyrate, carbon dioxide, and ammonia. Other amino acids are involved in more complicated metabolic reactions that give rise to these short-chain amino acids, sometimes with succinate, another common end product in plaque.

This is soluble in water and can be isolated from the raw wool by aqueous extraction. It contains potassium salts of fatty acids, such as oleic and stearic acids, and potassium carbonate is also present. The simpler organic acids, such as acetic, lactic, butyric, valeric, and capronic acids, have also been found both in the free state and as their potassium salts. Amino acids such as leucine, glycine, and tyrosine have been detected. Suint, therefore, is a complex mixture this might be expected because it is derived from sweat, which is known to be one of the means by which an animal discards unwanted waste products of its metabolism. 

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