Y-aminobutyrate and

The marked absorption of ambient CO2 by berries (50% of their volume at 15 °C) is accompanied by the incorporation of a small proportion of the C02 by phosphoenolpyruvate (p-carboxylation) and by malic acid synthesis. Malic acid is a key molecule during AM since it is also catabo-lized to ethanol, and y-aminobutyric and succinic acids. 

Giorgi O and Meek J. L. (1984) v-aminobutync acid turnover m rat striatum. Effects of glutamate and kainic add / Neurochem 42, 215-220 Graham L T Jr and Aprison M H (1969) Distribution of some enzymes associated with the metabolism of aspartate, glutamate, y-aminobutyrate, and glutamine in cat spinal cord /. Neurochem 16, 559-566... 

Valentin HE, Reiser S, Grays KJ. (2000). Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) formation from y-aminobutyrate and glutamate. Biotechnol Bioeng, 67, 291-299. 

Lindane is used predominately as a seed dressing and soil insecticide, for the control of ectoparasites of humans and domestic animals, for the control of locusts and grasshoppers, and as a residual spray to control the Anopheles vectors of malaria. Because of its relatively high volatility it is useful to control wood-boring insects of timber, fmit trees, and ornamental plants. The mode of action is not well understood but is thought to be competitive blocking of the y-aminobutyric acid (GABA) transmitter of synaptic nerve transmission. 

Mode of Motion. The cyclodienes, like lindane and toxaphene, affect the nerve axon produciag hyperactivity, convulsions, prostration, and death. The biochemical lesion is the competitive inhibition of the y-aminobutyric acid (GABA) neurotransmitter binding site of the nerve axon. Spray workers with lengthy exposure to dieldrin have suffered from prolonged and repeated central nervous system disturbances produciag epileptiform coavulsioas. Similar disturbances occurred ia workers heavily exposed to chlordecoae. 

Avermectins and Ivermectin. The avermectias are pentacycHc lactones isolated from fermentation products of Streptomjces avermitilis and ivermectin is a semisynthetic chemical, 22,23-dihydroavermectia (46). Ivermectin is effective in very low doses for the control of red spider mites on deciduous fmits, in baits for the control of imported fire ants, and as a parasiticide for Onchocerca volvulus in humans and for catde gmbs. These insecticides appear to function as agonists for the neuroinhibitory transmitter y-aminobutyric acid (GABA) (see Antiparasitic agents, avermectins). 

Strong acids or bases catalyze the hydrolysis of 2-pyrrohdinone to 4-aminobutanoic acid [y-aminobutyric acid [56-12-2] (GABA)]. GABA is involved in the functioning of the brain and nervous system and is of considerable interest as a potential dietary supplement (60). 

Another class of therapeutic agents is used for the treatment of certain genetic diseases or other enzymatic disorders caused by the dysfunction or absence of one particular enzyme. This often leads to an unwanted accumulation or imbalance of metaboUtes in the organism. Eor example, some anticonvulsive agents are inhibitors for y-aminobutyric acid aminotransferase [9037-67-6]. An imbalance of two neurotransmitters, glutamate and y-aminobutyric acid, is responsible for the symptoms. Inhibition of the enzyme leads to an increase of its substrate y-aminobutyric acid, decreasing the imbalance and subsequently relieving the symptoms of the disease. 

The American authors suggested (X) or (XI), already considered by Spath and Nikawitz for vasicine, and support for a formula of type (XI) was provided by Spath, Kuffner and Platzer, who, by condensing o-nitrobenzyl chloride with methyl y-aminobutyrate to o-nitrobenzyl-pyrrolidone (XII), reduction of this to the amino-compound (XII NOa —> NHj) and ring-closure in presence of phosphoryl chloride obtained the base d -pegene (XIII), m.p. 99-100°, identical with the product formed by the reduction of deoxychloropeganine. The same substance... 

Aminobutanoic acid known as y-aminobutyric acid (GABA), it is a y-amino acid and is involved in the transmission of nerve impulses... 

Certain amino acids and their derivatives, although not found in proteins, nonetheless are biochemically important. A few of the more notable examples are shown in Figure 4.5. y-Aminobutyric acid, or GABA, is produced by the decarboxylation of glutamic acid and is a potent neurotransmitter. Histamine, which is synthesized by decarboxylation of histidine, and serotonin, which is derived from tryptophan, similarly function as neurotransmitters and regulators. /3-Alanine is found in nature in the peptides carnosine and anserine and is a component of pantothenic acid (a vitamin), which is a part of coenzyme A. Epinephrine (also known as adrenaline), derived from tyrosine, is an important hormone. Penicillamine is a constituent of the penicillin antibiotics. Ornithine, betaine, homocysteine, and homoserine are important metabolic intermediates. Citrulline is the immediate precursor of arginine. 

Sleep and its modulation by N- and N,0-heterocyclic drugs that affect y-aminobutyric acid (GABA) receptor function 99AG(E)2852. 

Barnard EA, Skolnick P, Olsen RW et al (1998) International Union of Pharmacology. XV. Subtypes of y-aminobutyric acidA receptors classification on the basis of subunit structure and receptor function. Pharmacol Rev 50 291-313... 

Picrotoxin is a mixture of pircotin (non-toxic) and picrotoxinin, which occurs in the seeds of the Asiatic climber Anamirta cocculus (levent berry, cockles). It is a non-competitive antagonist at the y -aminobutyric acidA (GABAa) receptor. 

Tetanus is a disease caused by the release of neurotoxins from the anaerobic, spore-forming rod Clostridium tetani. The clostridial protein, tetanus toxin, possesses a protease activity which selectively degrades the pre-synaptic vesicle protein synaptobrevin, resulting in a block of glycine and y-aminobutyric acid (GABA) release from presynaptic terminals. Consistent with the loss of neurogenic motor inhibition, symptoms of tetanus include muscular rigidity and hyperreflexia. The clinical course is characterized by increased muscle tone and spasms, which first affect the masseter muscle and the muscles of the throat, neck and shoulders. Death occurs by respiratory failure or heart failure. 

Succinic semialdehyde (SSA) is synthesized in the mitochondria through transamination of y-aminobutyric acid (GABA) by GABA transaminase (GABA-T). Most of the SSA is oxidized by SSA dehydrogenase (SSA-DH) to form succinate, which is used for energy metabolism and results in the end products CO2 + H2O, which are expired. A small portion of SSA (<2%) is converted by SSA reductase (SSA-R) in the cytosol to GHB. GHB may also be oxidized back to SSA by GHB dehydrogenase (GHB-DH). 

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