Exposure to hyperbaric oxygen induces tumour necrosis factor-alpha (TNF-alpha) secretion from rat macrophages.
We investigated the secretion of TNF-alpha by monocytes and macrophages derived from the peripheral blood, spleen, and lungs after a single exposure to a therapeutic profile of hyperbaric oxygen (HBO). Rats were exposed for 90 min to either 100% oxygen at 0.28 MPa (2.8 atmospheres absolute) or air. Immediately after exposure, mononuclear cells were isolated from blood, spleen, and lungs and cultured for 18 h. The secretion of TNF-alpha from the cultured monocytes/macrophages was determined with and without stimulation with lipopolysaccharide (LPS). Exposure to hyperbaric oxygen induced a significant increase in the spontaneous ex vivo secretion of TNF-alpha (without LPS) by mononuclear cells from the blood, spleen, and lung (P < 0.05 from air controls). Stimulation with LPS after exposure to HBO induced a significant increase in TNF-alpha secretion by lung and spleen macrophages compared with air controls (P < 0.05). However, absolute TNF-alpha levels were not significantly higher than those achieved 'spontaneously' in macrophages exposed to HBO without LPS. Stimulation with LPS induced a marked increase in secretion of TNF-alpha from blood monocytes after exposure to air, but not after exposure to HBO. These results provide evidence in support of a role played by TNF-alpha in mediating HBO effects on different tissues and their immune responses.
Israel Naval Medical Institute, Immunological Research Unit, Haifa, Israel.
N
N
Lahat
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H
Bitterman
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Yaniv
A
A
Kinarty
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Bitterman
D000818:Animals; D002478:Cells, Cultured; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha