title: Release of soluble receptors for tumor necrosis factor (TNF) in relation to circulating TNF during experimental endotoxinemia.
abstract: Serial plasma samples from human volunteers obtained after intravenous administration of Escherichia coli endotoxin were analyzed for the presence of circulating soluble tumor necrosis factor receptors (sTNFR). A four- to fivefold increase of type A (p75) and type B (p55) sTNFR was observed 3 h after endotoxin challenge. Pretreatment of the volunteers with ibuprofen before the injection of endotoxin resulted in a slight increase (3.87 +/- 0.2 vs. 3.27 +/- 0.3 ng/ml) and temporal shift of sTNFR-A release concurrent to a marked augmentation of TNF levels (603 +/- 118 vs. 338 +/- 56 pg/ml) as compared to the group without ibuprofen pretreatment. There was a significant correlation between peak sTNFR-A levels and peak TNF levels in the individual probands (r = 0.52, P = 0.04). On the contrary, release kinetics and plasma concentrations of sTNFR-B were identical in both groups (7.38 +/- 0.69 vs. 7.44 +/- 0.33 ng/ml) and no correlation with individual TNF levels was observed. The amount of sTNFR liberated upon endotoxin challenge was not sufficient to block TNF-mediated cytotoxic effects. Our data indicate that the release in vivo of type A and type B sTNFR upon a short exposure to endotoxin is regulated differently.
authors.affiliation: Department of Internal Medicine and Research, University Hospital, Basel, Switzerland.
authors.forename: G A
authors.initials: GA
authors.lastname: Spinas
authors.forename: U
authors.initials: U
authors.lastname: Keller
authors.forename: M
authors.initials: M
authors.lastname: Brockhaus
mesh_terms: D000328:Adult; D001427:Bacterial Toxins / Q000097:blood; D004731:Endotoxins / Q000097:blood*; D004926:Escherichia coli; D006801:Humans; D007052:Ibuprofen / Q000494:pharmacology; D008297:Male; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D001427:Bacterial Toxins; D004731:Endotoxins; D011956:Receptors, Cell Surface; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D007052:Ibuprofen