Linked Life Data

6654894

Source:http://linkedlifedata.com/resource/pubmed/id/6654894

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1984-2-14
pubmed:abstractText
The present study provides strong evidence for the involvement of rat liver microsomal cytochrome b5 in the first reduction step of fatty acid chain elongation. The rate of reoxidation of NADH-reduced microsomal cytochrome b5 was markedly stimulated (up to 3-fold) by the addition of increasing concentrations of beta-ketohexadecanoyl-CoA (1-8 microM). A quantitative analysis of product formation, the effect of cyanide, and anaerobiosis completely exclude the possibility that desaturase activity accounted for the beta-ketohexadecanoyl-CoA-induced stimulation of the cytochrome b5 reoxidation rate. Using liver microsomes from untreated rats, the beta-keto substrate was found to stimulate the rate of reoxidation of cytochrome b5 by 30%. However, when liver microsomes from fat-free diet rats were employed the stimulation was more than 3-fold, suggesting that the beta-ketoacyl-CoA reductase is inducible by a high carbohydrate, fat-free diet. This study also provides evidence for the noninvolvement of cytochrome b5 in the terminal reaction step (second reduction step of chain elongation), which is catalyzed by the trans-2-enoyl-CoA reductase. Although trans-2-hexadecenoyl-CoA significantly stimulated the NADH-reduced cytochrome b5 reoxidation rate under aerobic conditions, it did not have any stimulatory effect under anaerobic conditions. One interpretation of these results is that the trans-2-hexadecenoyl-CoA is substrate for the microsomal delta 9 desaturase system. Consistent with this conclusion was the fact that the trans-2-hexadecenoyl-CoA inhibited the liver microsomal delta 9 desaturation of stearoyl-CoA to oleoyl-CoA.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14823-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Site of participation of cytochrome b5 in hepatic microsomal fatty acid chain elongation. Electron input in the first reduction step.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.