Effects of a 900-MHz electromagnetic field on oxidative stress parameters in rat lymphoid organs, polymorphonuclear leukocytes and plasma.

Archives of medical research · 2011 · Harm · Low evidence

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HarmLow evidencePaper 4447

Study snapshot

PublicationArchives of medical research · 2011

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

BACKGROUND AND AIMS: The present study investigated the effects of a 900-MHz electromagnetic field (EMF) for 2 h/day for 45 days on lymphoid organs (spleen, thymus, bone marrow), polymorphonuclear leukocytes (PMNs) and plasma of rats, focusing on changes in the enzymatic and nonenzymatic antioxidant system. We determined whether there is any difference between immature and mature rats in terms of oxidative damage caused by EMF and tested recovery groups to determine whether EMF-induced damage is reversible in immature and mature rats. METHODS: Twenty four immature and 24 mature rats were divided randomly and equally into six groups as follows: two control groups, immature (2 weeks old) and mature (10 weeks old); two groups were exposed to 900 MHz (28.2 ± 2.1 V/m) EMF for 2 h/day for 45 days. Two recovery groups were kept for 15 days after EMF exposure. RESULTS: Substantial, deleterious biochemical changes were observed in oxidative stress metabolism after EMF exposure. Antioxidant enzyme activity, glutathione levels in lymphoid organs and the antioxidant capacity of the plasma decreased, but lipid peroxidation and nitric oxide levels in PMNs and plasma and also myeloperoxidase activity in PMNs increased. Oxidative damage was tissue specific and improvements seen after the recovery period were limited, especially in immature rats. CONCLUSIONS: In the present study, much higher levels of irreversible oxidative damage were observed in the major lymphoid organs of immature rats than in mature rats.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal

Effect directionharm

PopulationImmature (2 weeks old) and mature (10 weeks old) rats

Sample size48

ExposureRF · 900 MHz · 2 h/day for 45 days (plus 15-day recovery groups)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

After 900 MHz EMF exposure (28.2 ± 2.1 V/m; 2 h/day for 45 days), antioxidant enzyme activity and glutathione levels in lymphoid organs and plasma antioxidant capacity decreased, while lipid peroxidation and nitric oxide levels in PMNs and plasma and myeloperoxidase activity in PMNs increased. Oxidative damage was tissue-specific and recovery over 15 days was limited, especially in immature rats.

Outcomes measured

Antioxidant enzyme activity (lymphoid organs)
Glutathione levels (lymphoid organs)
Plasma antioxidant capacity
Lipid peroxidation (PMNs and plasma)
Nitric oxide levels (PMNs and plasma)
Myeloperoxidase activity (PMNs)
Tissue-specific oxidative damage
Reversibility after recovery period

Limitations

Exposure metric reported as electric field strength (V/m) without SAR
No details provided in abstract on blinding, randomization procedures beyond group assignment, or sham exposure conditions
Specific statistical results and effect sizes not reported in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "2 h/day for 45 days (plus 15-day recovery groups)"
  },
  "population": "Immature (2 weeks old) and mature (10 weeks old) rats",
  "sample_size": 48,
  "outcomes": [
    "Antioxidant enzyme activity (lymphoid organs)",
    "Glutathione levels (lymphoid organs)",
    "Plasma antioxidant capacity",
    "Lipid peroxidation (PMNs and plasma)",
    "Nitric oxide levels (PMNs and plasma)",
    "Myeloperoxidase activity (PMNs)",
    "Tissue-specific oxidative damage",
    "Reversibility after recovery period"
  ],
  "main_findings": "After 900 MHz EMF exposure (28.2 ± 2.1 V/m; 2 h/day for 45 days), antioxidant enzyme activity and glutathione levels in lymphoid organs and plasma antioxidant capacity decreased, while lipid peroxidation and nitric oxide levels in PMNs and plasma and myeloperoxidase activity in PMNs increased. Oxidative damage was tissue-specific and recovery over 15 days was limited, especially in immature rats.",
  "effect_direction": "harm",
  "limitations": [
    "Exposure metric reported as electric field strength (V/m) without SAR",
    "No details provided in abstract on blinding, randomization procedures beyond group assignment, or sham exposure conditions",
    "Specific statistical results and effect sizes not reported in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "900 MHz",
    "RF-EMF",
    "rats",
    "oxidative stress",
    "antioxidants",
    "glutathione",
    "lipid peroxidation",
    "nitric oxide",
    "myeloperoxidase",
    "spleen",
    "thymus",
    "bone marrow",
    "polymorphonuclear leukocytes",
    "plasma",
    "immature vs mature",
    "recovery"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.arcmed.2011.06.001
PubMed: 21820603

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