title: Effect of hyperbaric oxygen on tissue distribution of mononuclear cell subsets in the rat.
abstract: In a previous study we found a significant temporary decrease in the ratio of CD4/CD8 (helper, inducer/suppressor, cytotoxic) T lymphocytes in the peripheral blood of healthy human volunteers after exposure to a single commonly used profile of hyperbaric oxygen (HBO). The transient nature of the changes suggested redistribution of T-cell subsets. The purpose of the present study was to verify such a redistribution and to locate possible target organs in an animal model. A single exposure of rats to HBO (0.28 MPa) induced a highly significant rapid decrease in the CD4/CD8 ratio in peripheral blood count (P < 0.0001), confirming our previous findings in humans. HBO also induced a significant increase in the CD4/CD8 ratio in the lungs and lymph nodes (P < 0.001) and a significant decrease in the ratio in the spleen (P < 0.01). Furthermore, exposure to HBO induced a significant increase in T cells bearing surface interleukin-2 receptors in the blood, spleen, lungs, and lymph glands (P < 0.001) and a significant decrease in T cells expressing alpha beta-receptors in the lungs (P < 0.001) and lymph glands (P < 0.05). Our findings suggest rapid T-cell activation after a brief exposure to HBO, with shifts of CD4 and CD8 subsets and variations in T-cell receptor type. These rapid changes in the parameters of cell-mediated immunity may represent the activation of protective mechanisms against the toxic effect of oxygen or the early stages of pulmonary oxygen toxicity.
authors.affiliation: Israel Naval Medical Institute, Haifa, Israel.
authors.forename: N
authors.initials: N
authors.lastname: Bitterman
authors.forename: N
authors.initials: N
authors.lastname: Lahat
authors.forename: T
authors.initials: T
authors.lastname: Rosenwald
authors.forename: A
authors.initials: A
authors.lastname: Kinarty
authors.forename: Y
authors.initials: Y
authors.lastname: Melamed
authors.forename: H
authors.initials: H
authors.lastname: Bitterman
mesh_terms: D000818:Animals; D016516:CD4-CD8 Ratio; D006931:Hyperbaric Oxygenation; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008168:Lung / Q000276:immunology*; D008221:Lymphoid Tissue / Q000276:immunology*; D008297:Male; D008856:Microscopy, Fluorescence; D010100:Oxygen / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D010100:Oxygen