Linked Life Data

2508746

Source:http://linkedlifedata.com/resource/pubmed/id/2508746

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-12-5
pubmed:abstractText
Activation of polymorphonuclear neutrophils (PMNL) leads to the release of arachidonate from cellular phospholipids via a phospholipase A2, and conversion of products of the 5-lipoxygenase pathway. Evidence to date indicates the dietary vitamin E ((R,R,R)-alpha-tocopherol) can influence both cyclooxygenase and phospholipase A2 activities and that the effect of this vitamin is cell/tissue specific. The present study was undertaken in order to examine the effects of varying dietary tocopherol on PMNL tocopherol content and 5-lipoxygenase product profile using the ionophore A23187 as stimulant in the presence and absence of exogenous arachidonate. Feeding semi-purified diets containing 0, 30 or 3000 ppm of (R,R,R)-alpha-tocopherol acetate to weanling rats for 17 weeks resulted in a dose-related enrichment of PMNL tocopherol. Stimulation of PMNL elicited a significant and rapid loss of tocopherol. When PMNL were stimulated with A23187 alone, the synthesis of 5-HETE, LTB4 and 19-hydroxy-LTB4 was decreased in proportion to increasing dietary tocopherol concentrations. However, when exogenous arachidonate was provided with A23187, intermediate amounts of dietary tocopherol (30 ppm) still suppressed the formation of 5-lipoxygenase products, but high doses (3000 ppm) did not have any additional inhibitory effect. This differential response to high concentrations of vitamin E in the presence and absence of exogenous arachidonate highly suggest that at these concentrations, tocopherol may act principally at the level of substrate release whereas at lower concentrations, 5-lipoxygenase is inhibited. Data from this study demonstrated that attenuation of the formation of 5-lipoxygenase products in PMNL can be achieved by dietary vitamin E enrichment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
1005
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
265-9
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Effects of dietary vitamin E on the biosynthesis of 5-lipoxygenase products by rat polymorphonuclear leukocytes (PMNL).
pubmed:affiliation
Department of Biochemistry, School of Medicine, University of Ottawa, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't