The phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst in rat peritoneal neutrophils is increased by a 0.1 mT (60 Hz) magnetic field.

Abstract

Magnetic fields (MF) may affect biological systems by increasing free radical concentrations. To test this, we have investigated whether low frequency (60 Hz) low intensity (0.1 mT) MF can modulate the phorbol 12-myristate 13- acetate (PMA) induced respiratory burst in primed rat peritoneal neutrophils, followed in real time using the dye 2',7'-dichlorofluorescin (DCFH), which reacts with free radical-derived oxidants such as H2O2 (which is formed from the dismutation of superoxide) to become 2',7'-dichlorofluorecein (DCF), a highly fluorescent compound. In the presence of the MF, a 12.4% increase in the fluorescence signal was observed in PMA-stimulated neutrophils (n = 5, P < 0.02, 18 pairs of measurements). We believe this represents the first experimental observation of MF influencing events involving free radical species generated during signal transduction in living cells.

AI evidence extraction

Main findings

In the presence of a 60 Hz, 0.1 mT magnetic field, PMA-stimulated rat peritoneal neutrophils showed a 12.4% increase in DCF fluorescence compared with paired measurements without the field (n=5; 18 pairs; P<0.02).

Outcomes measured

• PMA-induced respiratory burst / oxidative burst (DCFH to DCF fluorescence as a proxy for free radical-derived oxidants such as H2O2)

Limitations

• In vitro experiment in rat cells; generalizability to humans not addressed.
• Small sample size (n=5) despite multiple paired measurements.
• Outcome is an indirect fluorescence-based proxy for oxidant production (DCFH/DCF).
• Exposure duration and other exposure conditions are not described in the abstract.

Suggested hubs

• occupational-exposure (0.25)
  Study involves ELF (60 Hz) magnetic field exposure, which is commonly relevant to occupational ELF exposure contexts, though no specific setting is stated.

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        "frequency_mhz": 0.059999999999999997779553950749686919152736663818359375,
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    },
    "population": "Primed rat peritoneal neutrophils",
    "sample_size": 5,
    "outcomes": [
        "PMA-induced respiratory burst / oxidative burst (DCFH to DCF fluorescence as a proxy for free radical-derived oxidants such as H2O2)"
    ],
    "main_findings": "In the presence of a 60 Hz, 0.1 mT magnetic field, PMA-stimulated rat peritoneal neutrophils showed a 12.4% increase in DCF fluorescence compared with paired measurements without the field (n=5; 18 pairs; P<0.02).",
    "effect_direction": "harm",
    "limitations": [
        "In vitro experiment in rat cells; generalizability to humans not addressed.",
        "Small sample size (n=5) despite multiple paired measurements.",
        "Outcome is an indirect fluorescence-based proxy for oxidant production (DCFH/DCF).",
        "Exposure duration and other exposure conditions are not described in the abstract."
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "extremely low frequency",
        "ELF",
        "60 Hz",
        "0.1 mT",
        "magnetic field",
        "oxidative burst",
        "respiratory burst",
        "neutrophils",
        "PMA",
        "free radicals",
        "reactive oxygen species",
        "DCFH",
        "DCF"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.25,
            "reason": "Study involves ELF (60 Hz) magnetic field exposure, which is commonly relevant to occupational ELF exposure contexts, though no specific setting is stated."
        }
    ]
}

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