Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1991-11-13
pubmed:abstractText
Rat peritoneal polymorphonuclear leukocytes (PMN) elicited with oyster glycogen contain a Ca(2+)-independent nitric oxide (NO) synthase which is induced in vivo in a time-dependent manner. When washed PMN containing low levels of enzyme activity were cultured ex vivo further expression of NO synthase was observed. This was inhibited by cycloheximide indicating that de novo synthesis of the enzyme occurred during the ex vivo incubation. Enzyme activity was enhanced by interferon (IFN)-gamma, but not by tumor necrosis factor (TNF)-alpha when added ex vivo. However, IFN-gamma and TNF-alpha synergized to increase further the expression of NO synthase. Treatment of rats with dexamethasone inhibited the induction of NO synthase in elicited PMN. This treatment reduced the accumulation of PMN by approximately 30%, without affecting cell viability. Dexamethasone also inhibited the induction of the NO synthase ex vivo in a concentration-dependent manner. Furthermore, the enhanced enzyme activity following treatment of PMN with cytokines was also inhibited by dexamethasone. Once induced, dexamethasone did not affect enzyme activity. These data indicate that PMN elicited in the rat peritoneum with oyster glycogen express an NO synthase in vivo and ex vivo. The induction of the enzyme can be further stimulated ex vivo with IFN-gamma and TNF-alpha and inhibited by dexamethasone. The inhibition of the induction of NO synthase in the PMN by dexamethasone may contribute to the anti-inflammatory activity of this and other glucocorticoids.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2523-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Induction of nitric oxide synthase in rat peritoneal neutrophils and its inhibition by dexamethasone.
pubmed:affiliation
Wellcome Research Laboratories, Beckenham, Kent, Great Britain.
pubmed:publicationType
Journal Article