[Effects of extremely low frequency electromagnetic fields on male reproduction in mice].

Abstract

OBJECTIVE: To investigate the effects of extremely low frequency electromagnetic fields (ELF EMFs) on male reproduction in mice. METHODS: 94 adult male mice were exposed to 50 Hz sinusoidal electromagnetic fields of 0.2, 3.2 or 6.4 mT for 2 weeks or 4 weeks. Testicular histology and weight, sperm amount, sperm motility and morphology were measured. The percentages of different ploidy cells and cell phases, and DNA content of testis cells were estimated by flow cytometry. The micronucleus rate of bone-marrow cell was also observed. RESULTS: The testicular weight of the mice exposed to 6.4 mT for 4 weeks [(76.06 +/- 32.25) mg] was significantly lower than that of the control [(111.44 +/- 19.99) mg, P < 0.05]; no significant histopathological changes were observed on the testis in EMFs exposed mice;the sperm amount was decreased after EMFs exposure for 4 weeks, and those of the mice exposed to 0.2 mT and 6.4 mT for 4 weeks [(4.87 +/- 0.94) x 10(6)/ml and (4.30 +/- 1.89) x 10(6)/ml respectively] were significantly lower than that of the control [(6.67 +/- 0.70) x 10(6)/ml, P < 0.05]; the rates of sperm motility also showed a decline. After 0.2, 3.2 or 6.4 mT EMFs exposure for 2 weeks, the deformity rates of sperm [(7.416 +/- 3.352)%, (6.862 +/- 2.947)% and (8.112 +/- 4.615)% respectively] were significantly higher than that of the control [(4.098 +/- 2.028)%, P < 0.01]. Similarly, those of the mice exposed for 4 weeks [(10.267 +/- 3.836)%, (11.027 +/- 7.059)%, (8.814 +/- 3.678)% respectively] were higher than that of the control [(3.714 +/- 1.830)%]. After 6.4 mT exposure for 2 weeks, the percentages of 1C testis cells [(69.56 +/- 4.07)%] was significantly lower than that of the control [(73.45 +/- 3.10)%, P < 0.05]. There were not any remarkable changes in those of 2C, 4C cells. DNA content in different ploidy cells of the mice exposed to 6.4 mT was decreased. Moreover, the cell percentage in S phase was increased significantly (P < 0.01). CONCLUSION: ELF EMFs exposure may have some adverse effects on reproduction in mice.

AI evidence extraction

Main findings

Male mice exposed to 50 Hz sinusoidal fields (0.2, 3.2, or 6.4 mT) showed reduced testicular weight at 6.4 mT after 4 weeks versus control, decreased sperm amount after 4 weeks (significant at 0.2 and 6.4 mT), declines in sperm motility, and increased sperm deformity rates after both 2 and 4 weeks. No significant testicular histopathological changes were observed. At 6.4 mT for 2 weeks, the percentage of 1C testis cells and DNA content were decreased, and S-phase cell percentage increased; 2C and 4C cells did not show remarkable changes.

Outcomes measured

• Testicular weight
• Testicular histology
• Sperm amount (count)
• Sperm motility
• Sperm morphology/deformity rate
• Testis cell ploidy distribution (1C/2C/4C)
• DNA content of testis cells
• Cell cycle phase distribution (S phase)
• Bone-marrow micronucleus rate

Limitations

• Exposure source/context (e.g., occupational vs environmental) not specified
• Micronucleus rate results not reported in the abstract
• Randomization/blinding and other design details not described in the abstract

Suggested hubs

• occupational-exposure (0.35)
  Published in an industrial hygiene/occupational diseases journal and uses ELF (50 Hz) exposure relevant to occupational settings.

{
    "study_type": "animal",
    "exposure": {
        "band": "ELF",
        "source": null,
        "frequency_mhz": 5.00000000000000023960868011929647991564706899225711822509765625e-5,
        "sar_wkg": null,
        "duration": "2 weeks or 4 weeks"
    },
    "population": "Adult male mice",
    "sample_size": 94,
    "outcomes": [
        "Testicular weight",
        "Testicular histology",
        "Sperm amount (count)",
        "Sperm motility",
        "Sperm morphology/deformity rate",
        "Testis cell ploidy distribution (1C/2C/4C)",
        "DNA content of testis cells",
        "Cell cycle phase distribution (S phase)",
        "Bone-marrow micronucleus rate"
    ],
    "main_findings": "Male mice exposed to 50 Hz sinusoidal fields (0.2, 3.2, or 6.4 mT) showed reduced testicular weight at 6.4 mT after 4 weeks versus control, decreased sperm amount after 4 weeks (significant at 0.2 and 6.4 mT), declines in sperm motility, and increased sperm deformity rates after both 2 and 4 weeks. No significant testicular histopathological changes were observed. At 6.4 mT for 2 weeks, the percentage of 1C testis cells and DNA content were decreased, and S-phase cell percentage increased; 2C and 4C cells did not show remarkable changes.",
    "effect_direction": "harm",
    "limitations": [
        "Exposure source/context (e.g., occupational vs environmental) not specified",
        "Micronucleus rate results not reported in the abstract",
        "Randomization/blinding and other design details not described in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "extremely low frequency",
        "ELF EMF",
        "50 Hz",
        "magnetic field",
        "mT",
        "mice",
        "male reproduction",
        "testis",
        "sperm count",
        "sperm motility",
        "sperm morphology",
        "flow cytometry",
        "cell cycle",
        "DNA content"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.34999999999999997779553950749686919152736663818359375,
            "reason": "Published in an industrial hygiene/occupational diseases journal and uses ELF (50 Hz) exposure relevant to occupational settings."
        }
    ]
}

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