In Vitro Effects of Nitrogen Dioxide on the Release of Superoxide Anions, Tnf-α, and IL-8 by HL60-Macrophages and Bovine Alveolar Macrophages

Modulation of cytokine production by interferential current in differentiated HL-60 cells

The influence of interferential current (IFC) on the release of four cytokines was investigated. IFC is an amplitude-modulated 4 kHz current used in therapeutic applications. Human promyelocytes (HL-60) were differentiated to monocytes/macrophages by treatment with calcitriol. Release of tumor necrosis factor alpha (TNFalpha) and interleukines 1beta, 6, and 8 (IL-1beta, IL-6, and IL-8) into the supernatant was measured after exposure to IFC at different modulation frequencies. TNFalpha release was stimulated about twofold by 4 kHz sine waves alone. The influences of exposure time (5-30 min) and current density (2.5-2500 microA/c m(2)) were tested. A maximum field effect was found at an exposure time of 15 min and a current density of 250 microA/cm(2). With these exposure conditions (15 min and 250 microA/cm(2) ), cells were treated at different modulation frequencies and reacted for TNFalpha, IL-1beta, and IL-8 release in a complex manner. Within the frequencies studied (0-125 Hz), we found stimulation as well as depression of the release. In a second run the cells were activated by pretreatment with 10 microg/ml lipopolysaccharide (LPS) and exposed in the same way as the nonactivated cells. Again the modulation frequency influenced, in a complex way, the induction of TNFalpha, IL-1beta, and IL-8, resulting in a pattern of stimulation and depression of release different from that found in nonactivated cells. For IL-6 production no significant changes were detected in activated or non-activated cells.

Influence of salbutamol and isoproterenol on the production of TNF and reactive oxygen species by bovine alveolar macrophages and calcitriol differentiated HL-60 cells

The influence of the beta-adrenergic agonists Salbutamol and Isoproterenol on the release of reactive oxygen species and Tumor Necrosis Factor (TNF) was tested with bovine alveolar macrophages and HL-60 cells differentiated to macrophages by calcitriol. The production of reactive oxygen species was analyzed by a microplate assay using dichlorofluorescein-diacetate. It could be shown that this method almost exclusively measures superoxide anions. TNF was determined by a bioassay with WEHI cells. The superoxide anion production was stimulated by Zymosan, the TNF release by LPS. By incubation with 5 x 10(-6) and 5 x 10(-7) M Salbutamol or 5 x 10(-7) and 5 x 10(-8) M Isoproterenol prior to the stimulation, the production of superoxide anions as well as of TNF was inhibited to a significant degree. The inhibitory effects of the adrenergic agonists were completely or at least partially inhibited by the respective antagonists, ICI 118.551 and Propranolol, respectively.