Adrenic acid

A defect in the capability of the enzyme 5-6-desaturase to convert linoleic acid to y-linolenic acid is known to occur in patients with atopic dermatitis (9). Patients with atopic eczema have a dietary deficiency in metabolites of linoleic y-linolenic acid, dihomo-y-linolenic acid, arachidonic acid, adrenic acid, and docosapentaenoic acid caused by a reduced rate of activity in the 5-6-desturase enzyme (8). Galli et al. compared blood samples from babies born to parents who suffered from atopic eczema. Results showed... 

We examined the effect of DHA on A9 desaturase activity in hepatic microsomes and fatty acid composition in young SHR fed either a DHA-enriched diet or a control diet for 6 wk. It was noted that A9 desaturase activity was decreased by 53% in DHA-fed SHR and was accompanied by an increase in 16 0 and a reduction in 16 ln-7 concentration in hepatic microsomes. The DHA diet also increased the levels of EPA and DHA. The n-6 fatty acid concentration was also affected in DHA-fed SHR as reflected by a decrease in GLA, AA, adrenic acid (22 4n-6), and docosapentaenoic acid (22 5n-6). A higher proportion of DGLA and a lower proportion of AA are indicative of impaired A5 desaturase activity (120). The alterations in fatty acid composition and... 

Trivial names a-linolenic acid, linoleic acid, y-linolenic acid, arachidonic acid, adrenic acid. 

In addition to AA, a 20-caibon fatty acid with four olefins in an omega-6 configuration (20 4, n-6), CYPs can utilize other PUFAs as substrates. Notably, CYPs can metabolize adrenic acid (16 2, n-6), linoleic add (LA, 18 2, n-6), gaituna... 

Hagve TA, Christophersen BO (1986) Evidence for retroconversion of adrenic acid (22 4(n-6)) and docosahexaenoic acid (22 6(n-3)) in isolated liver cells. Biochim Biophys Acta 875 165-173... 

Dietary n-6 PUFAs include the fatty acids, LA (C18 2n-6), y-linolenic acid (C18 3n-6), dihomo-y-linolenic acid (C20 3n-6), arachidonic acid (AA C20 4n-6), adrenic acid (C22 4n-6) and docosapentaenoic acid (C22 5n-6 National Academy of Sciences et al., 2005). LA is an essential fatty acid because humans cannot synthesize it. Without dietary LA, deficiency occurs, producing adverse clinical symptoms, including reduced growth and a scaly rash (National Academy of Sciences et al., 2005). In the body, n-6 PUFAs function as a component of structural cell... 

C. It is secreted along with noradrenaline by the adrenal medulla, from which it may be obtained. It may be synthesized from catechol. It is used as the acid tartrate in the treatment of allergic reactions and circulatory collapse. It is included in some local anaesthetic injections in order to constrict blood vessels locally and slow the disappearance of anaesthetic from the site of injection. Ultimately it induces cellular activation of phosphorylase which promotes catabolism of glycogen to glucose. 

The outer layer or cortex of the adrenal gland is the source of a large group of sub stances known as corticosteroids Like the bile acids they are derived from cholesterol by oxidation with cleavage of a portion of the alkyl substituent on the D ring Cortisol IS the most abundant of the corticosteroids but cortisone is probably the best known Cortisone is commonly prescribed as an antiinflammatory drug especially m the treat ment of rheumatoid arthritis... 

Another series of antiinflammatory carboxyhc acids that ate derived from cortienic acid (107), a minor adrenal metabohte, has been described (104,105). Esterification of both the 17a-hydroxyl group and the carboxyhc acid of (107) were requited to develop a compound of high topical potency with low systemic activity. Peak activity was generally associated with a 17a-propionoxy group and a 17P- uoromethoxy carbonyl (eg, (108)), or 17P-methoxycarbonyl residue. 

Sulfoxides occur widely in small concentrations in plant and animal tissues, eg, aHyl vinyl sulfoxide [81898-53-5] in garlic oil and 2,2 -sulfinylbisethanol [3085-45-8] as fatty esters in the adrenal cortex (1,2). Homologous methyl sulfinyl alkyl isothiocyanates, which are represented by the formula CH3SO(CH2) NCS, where n = 3 [37791-20-1], 4 [4478-93-7], 5 [646-23-1], 8 [75272-81-0], 9 [39036-83-4], or 10 [39036-84-5], have been isolated from a number of mustard oils in which they occur as glucosides (3). Two methylsulfinyl amino acids have also been reported methionine sulfoxide [454-41-1] from cockroaches and the sulfoxide of i -methylcysteine, 3-(methylsulfinyl)alaiiine [4740-94-7]. The latter is the dominant sulfur-containing amino acid in turnips and may account in part for their characteristic odor (4). 

The adrenal glands and pituitary glands have the highest tissue concentration of ascorbic acid. The brain, Hver, and spleen, however, represent the largest contribution to the body pool. Plasma and leukocyte ascorbic acid levels decrease with increasing age (152). Elderly people require higher ascorbic acid intakes than children to reach the same plasma and tissue concentration (153). 

Relatively Httie is known about the bioavailabiUty of pantothenic acid in human beings, and only approximately 50% of pantothenic acid present in the diet is actually absorbed (10). Liver, adrenal glands, kidneys, brain, and testes contain high concentrations of pantothenic acid. In healthy adults, the total amount of pantothenic acid present in whole blood is estimated to be 1 mg/L. A significant (2—7 mg/d) difference is observed among different age-group individuals with respect to pantothenic acid intake and urinary excretion, indicating differences in the rate of metaboHsm of pantothenic acid. 

The original commercial source of E was extraction from bovine adrenal glands (5). This was replaced by a synthetic route for E and NE (Eig. 1) similar to the original pubHshed route of synthesis (6). Eriedel-Crafts acylation of catechol [120-80-9] with chloroacetyl chloride yields chloroacetocatechol [99-40-1]. Displacement of the chlorine by methylamine yields the methylamine derivative, adrenalone [99-45-6] which on catalytic reduction yields (+)-epinephrine [329-65-7]. Substitution of ammonia for methylamine in the sequence yields the amino derivative noradrenalone [499-61-6] which on reduction yields (+)-norepinephrine [138-65-8]. The racemic compounds were resolved with (+)-tartaric acid to give the physiologically active (—)-enantiomers. The commercial synthesis of E and related compounds has been reviewed (27). The synthetic route for L-3,4-dihydroxyphenylalanine [59-92-7] (l-DOPA) has been described (28). 

Catecholamine biosynthesis begins with the uptake of the amino acid tyrosine into the sympathetic neuronal cytoplasm, and conversion to DOPA by tyrosine hydroxylase. This enzyme is highly localized to the adrenal medulla, sympathetic nerves, and central adrenergic and dopaminergic nerves. Tyrosine hydroxylase activity is subject to feedback inhibition by its products DOPA, NE, and DA, and is the rate-limiting step in catecholamine synthesis the enzyme can be blocked by the competitive inhibitor a-methyl-/)-tyrosine (31). 

The pathways for liberation of fatty acids from triacylglycerols, either from adipose cells or from the diet, are shown in Figures 24.2 and 24.3. Fatty acids are mobilized from adipocytes in response to hormone messengers such as adren-... 

Pregnenolone is transported from the mitochondria to the ER, where a hydroxyl oxidation and migration of the double bond yield progesterone. Pregnenolone synthesis in the adrenal cortex is activated by adrenocorticotropic hormone (ACTH), a peptide of 39 amino acid residues secreted by the anterior pituitary gland. 

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