4-Aminobutyric

See also g-Aminobutyric acid.) PYRROLE AND PYRROLE DERIVATIVES] (Vol 20)... 

COALCONVERSIONPROCESSES - CLEANING AND DESULFURIZATION] (Vol 6) Gamma-aminobutyric acid (GABA)... 

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). 

Picrotoxin has been instmmental in estabUshing an inhibitory neurotransmitter role for the amino acid, gamma-aminobutyric acid (GABA), quantitatively the most important inhibitory neurotransmitter in the mammalian CNS. Whereas glycine is predominately localized in the spinal cord, GABA... 

Fig. 9. Stmcture of nisin where Dha = dehydroalanine Dhb = dehydrobutyrine Abu = a-aminobutyric acid Ala-S-Ala = me50-lanthionine and Abu-S-Ala = t/ireo-methyllanthionine. The first amino acid residue (Ala or Abu) of the lanthionine or methyUanthionine is a D residue all other amino...

MeVal = A-methylvaline and Abu = a-aminobutyric acid. The dotted lines indicate hydrogen bonds. 

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. 

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