Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subtoxic doses of endotoxin (salmonella abortus equi lipopolysaccharide, LPS) (5 micrograms/kg i.p.) or tumor necrosis factor alpha (TNF alpha) (15 micrograms/kg i.v.) induced fulminant hepatitis within 8 hr, when mice had been sensitized by a subtoxic dose of D-galactosamine (700 mg/kg i.p.). LPS-treatment led to the release of TNF into the circulation, independently of the presence of D-galactosamine. The TNF-dependent development of hepatitis was accompanied by a severe lymphopenia and neutrophilia as assessed by leukocyte differential count. The total leukocyte count was not significantly affected. Lymphopenia and neutrophilia were induced by LPS or TNF alpha alone; however, the differential count was not influenced by D-galactosamine. A quantity of 260 micrograms/kg phorbol myristate acetate (PMA) i.p. or 5 micrograms/kg platelet activating factor (PAF) i.v. or 3.3 mg/kg N-formyl-methionyl-leucyl-phenylalanine methylester (FMLP) i.v. or 167 mg/kg zymosan i.v. also caused lymphopenia and neutrophilia in mice. However, none of these agents induced the production of systemic TNF and therefore failed to induce hepatitis in D-galactosamine-sensitized mice. In LPS-insensitive C3H/HeJ mice administration of LPS produced neither differential count changes nor hepatitis while both events were observed when TNF alpha was given. This shows that TNF alpha alone gives rise to lymphopenia/neutrophilia as well as hepatitis independent of LPS. When the action of TNF alpha was blocked by anti TNF alpha antiserum pretreatment of LPS-sensitive mice, the animals were protected against LPS-induced hepatitis. However, lymphopenia and neutrophilia still occurred to a similar extent. The involvement of a putative additional mediator of LPS-induced leukocyte alterations was checked. The findings suggest that this mediator, if present, is different from IL-1, IL-2, eicosanoids or superoxide. We conclude from our findings that changes in leukocyte numbers and composition following D-galactosamine LPS or D-galactosamine/TNF alpha administration is an epiphenomenon rather than a causal event of leukocyte stimulation in the process of inducing a fulminant hepatitis in mice.
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PMID:Leukocyte alterations do not account for hepatitis induced by endotoxin or TNF alpha in galactosamine-sensitized mice. 240 85

Antibody neutralization studies have established interferon gamma (IFN-gamma) as a critical mediator of endotoxic shock. The advent of IFN-gamma receptor negative (IFN gamma R-/-) mutant mice has enabled a more direct assessment of the role of IFN-gamma in endotoxin (lipopolysaccharide [LPS]-induced shock. We report that IFN gamma R-/- mice have an increased resistance to LPS-induced toxicity, this resistance manifesting well before the synthesis and release of LPS-induced IFN-gamma. LPS-induced lymphopenia, thrombocytopenia, and weight loss seen in wild-type mice were attenuated in IFN gamma R-/- mice. IFN gamma R-/- mice tolerated 100-1,000 times more LPS than the minimum lethal dose for wild-type mice in a D-galactosamine (D-GalN)/LPS model. Serum tumor necrosis factor (TNF) levels were 10-fold reduced in mutant mice given LPS or LPS/D-GalN. Bone marrow and splenic macrophages from IFN gamma R-/- mice had a four- to sixfold decreased LPS-binding capacity which correlated with similar reduction in CD14. Serum from mutant mice reduced macrophage LPS binding by a further 50%, although LPS binding protein was only 10% reduced. The expression of TNF receptor I (p55) and II (p75) was identical between wild-type and mutant mice. Thus, depressed TNF synthesis, diminished expression of CD14, and low plasma LPS-binding capacity, in addition to blocked IFN-gamma signaling in the mutant mice, likely to combine to manifest in the resistant phenotype of IFN gamma R-/- mice to endotoxin.
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PMID:Interferon gamma receptor deficient mice are resistant to endotoxic shock. 816 30