Radiofrequency radiation (900 MHz)-induced DNA damage and cell cycle arrest in testicular germ cells in swiss albino mice

Abstract

Even though there are contradictory reports regarding the cellular and molecular changes induced by mobile phone emitted radiofrequency radiation (RFR), the possibility of any biological effect cannot be ruled out. In view of a widespread and extensive use of mobile phones, this study evaluates alterations in male germ cell transformation kinetics following RFR exposure and after recovery. Swiss albino mice were exposed to RFR (900 MHz) for 4 h and 8 h duration per day for 35 days. One group of animals was terminated after the exposure period, while others were kept for an additional 35 days post-exposure. RFR exposure caused depolarization of mitochondrial membranes resulting in destabilized cellular redox homeostasis. Statistically significant increases in the damage index in germ cells and sperm head defects were noted in RFR-exposed animals. Flow cytometric estimation of germ cell subtypes in mice testis revealed 2.5-fold increases in spermatogonial populations with significant decreases in spermatids. Almost fourfold reduction in spermatogonia to spermatid turnover (1C:2C) and three times reduction in primary spermatocyte to spermatid turnover (1C:4C) was found indicating arrest in the premeiotic stage of spermatogenesis, which resulted in loss of post-meiotic germ cells apparent from testis histology and low sperm count in RFR-exposed animals. Histological alterations such as sloughing of immature germ cells into the seminiferous tubule lumen, epithelium depletion and maturation arrest were also observed. However, all these changes showed recovery to varied degrees following the post-exposure period indicating that the adverse effects of RFR on mice germ cells are detrimental but reversible. To conclude, RFR exposure-induced oxidative stress causes DNA damage in germ cells, which alters cell cycle progression leading to low sperm count in mice.

AI evidence extraction

Main findings

In Swiss albino mice exposed to 900 MHz radiofrequency radiation for 35 days, the study reported significant increases in germ-cell DNA damage and sperm head defects, mitochondrial membrane depolarization, disrupted redox homeostasis, altered germ-cell populations, and evidence of premeiotic arrest with reduced spermatids and low sperm count. Histological abnormalities were observed in the testis, and these adverse changes showed partial to variable recovery after a 35-day post-exposure period.

Outcomes measured

• DNA damage in germ cells
• cell cycle arrest/premeiotic arrest in spermatogenesis
• mitochondrial membrane depolarization
• oxidative stress/redox imbalance
• sperm head defects
• changes in germ cell subtypes
• reduced spermatid population
• reduced spermatogonia-to-spermatid and primary spermatocyte-to-spermatid turnover
• histological testicular alterations
• low sperm count
• post-exposure recovery/reversibility

Limitations

• Animal study
• Sample size not stated in abstract
• Abstract notes contradictory reports in the literature
• Recovery was variable rather than complete

{
    "study_type": "animal",
    "exposure": {
        "band": "RF",
        "source": "mobile phone",
        "frequency_mhz": 900,
        "sar_wkg": null,
        "duration": "4 h/day or 8 h/day for 35 days; some animals assessed after an additional 35-day post-exposure recovery"
    },
    "population": "Swiss albino mice; male germ cells/testis",
    "sample_size": null,
    "outcomes": [
        "DNA damage in germ cells",
        "cell cycle arrest/premeiotic arrest in spermatogenesis",
        "mitochondrial membrane depolarization",
        "oxidative stress/redox imbalance",
        "sperm head defects",
        "changes in germ cell subtypes",
        "reduced spermatid population",
        "reduced spermatogonia-to-spermatid and primary spermatocyte-to-spermatid turnover",
        "histological testicular alterations",
        "low sperm count",
        "post-exposure recovery/reversibility"
    ],
    "main_findings": "In Swiss albino mice exposed to 900 MHz radiofrequency radiation for 35 days, the study reported significant increases in germ-cell DNA damage and sperm head defects, mitochondrial membrane depolarization, disrupted redox homeostasis, altered germ-cell populations, and evidence of premeiotic arrest with reduced spermatids and low sperm count. Histological abnormalities were observed in the testis, and these adverse changes showed partial to variable recovery after a 35-day post-exposure period.",
    "effect_direction": "harm",
    "limitations": [
        "Animal study",
        "Sample size not stated in abstract",
        "Abstract notes contradictory reports in the literature",
        "Recovery was variable rather than complete"
    ],
    "evidence_strength": "low",
    "confidence": 0.939999999999999946709294817992486059665679931640625,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "radiofrequency radiation",
        "900 MHz",
        "mobile phone",
        "Swiss albino mice",
        "testis",
        "germ cells",
        "DNA damage",
        "oxidative stress",
        "cell cycle arrest",
        "spermatogenesis",
        "sperm count",
        "histology"
    ],
    "suggested_hubs": []
}

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