title: Ionizing radiation at low doses induces inflammatory reactions in human blood.
abstract: Irradiation of whole blood with 137Cs gamma rays intensifies the oxidative burst. Oxidant production was used as an indicator of inflammatory cell reactions and was measured by luminol-amplified chemiluminescence after treatment with inflammatory activators including bacteria, the neutrophil taxin formyl-Met-Leu-Phe, the Ca2+ ionophore A23187, the detergent saponin, and the tumor promoter phorbol ester. The irradiation response is dose-dependent up to about 100 microGy, is detectable within minutes, persists at least 1 h, and is transmitted intercellularly by a soluble mediator. The response is completely inhibited by Ca2+ sequestration in the presence of A23187 or by adenosine, indicating its Ca2+ dependency, and by the phospholipase A2 blocker p-bromphenacyl bromide. However, inhibition by the cyclooxygenase blocker aspirin is sporadic or absent. Blood taken after diagnostic examination of lungs with X rays also exhibited intensified chemiluminescence. These reactions implicate a role for specific amplifying mediator pathways, especially metabolites of the arachidonic acid cascade, in the response: "damage and repair" to cells or DNA plays little or no role. Our results provide evidence for a new mechanism of radiation action with possible consequences for the homeostasis of reactions involving inflammation and second messengers in human health and early development.
authors.affiliation: Department of Biology, University of Bremen, Federal Republic of Germany.
authors.forename: M G
authors.initials: MG
authors.lastname: Vicker
authors.forename: H
authors.initials: H
authors.lastname: Bultmann
authors.forename: U
authors.initials: U
authors.lastname: Glade
authors.forename: T
authors.initials: T
authors.lastname: Häfker
mesh_terms: D016718:Arachidonic Acid / Q000494:pharmacology; D001769:Blood / Q000528:radiation effects*; D001773:Blood Cells / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D000001:Calcimycin / Q000494:pharmacology; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000502:physiology; D005720:Gamma Rays; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000503:physiopathology; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D011829:Radiation Dosage; D016897:Respiratory Burst / Q000187:drug effects / Q000528:radiation effects; D012503:Saponins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D012503:Saponins; D016718:Arachidonic Acid; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D008165:Luminol; D010741:Phospholipases A; D054467:Phospholipases A2; D013755:Tetradecanoylphorbol Acetate