Ultrastructural alterations and occurrence of apoptosis in developing follicles exposed to low frequency electromagnetic field in rat ovary.

Pakistan journal of biological sciences : PJBS · 2007 · Harm · Low evidence

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HarmLow evidencePaper 3376

Study snapshot

PublicationPakistan journal of biological sciences : PJBS · 2007

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Humans are continuously exposed to harmful environmental factors, including Electromagnetic Fields (EMF) produced by home appliances, diagnostic tools and industrial instruments. The present study investigates morphologically the effects of EMF on ovarian follicles. Female Wistar rats were exposed to 3 mili Tesla EMF for 4 h day(-1) for 4 months, the ovaries from both experimental and control groups were processed for Transmission Electron Microscopy (TEM) and TUNEL reaction technique. TEM revealed that in the oocytes from experimental group the nuclei were shrunken and zona pellucida appeared narrower than those in the control group. The number of microvilli were decreased significantly and in their cytoplasm there were several lipid droplets and organels were dispersed. Signs of apoptosis such as condensed nuclei, chromatin margination and nuclear membrane dilatation were common in granulosa and corona radiata cells from the EMF-exposed rats than those from the control group. Primary morphological changes in the granulosa cells from this group were retraction of granulosa cells, loss of microvilli and condensation or loss of mitochondrial cristae. The morphological changes in oocytes seem to indicate the cytotoxic effect of EMF and the changes occurred in granulosa cells coincide with initiation of apoptosis in granulosa cells. Present results suggest that EMF exposure may interfere with normal process of folliculogenesis.

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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

PopulationFemale Wistar rats (ovary/follicles)

Sample sizeNot supplied

ExposureELF · 4 h/day for 4 months

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Female Wistar rats exposed to a 3 mT low-frequency EMF for 4 h/day for 4 months showed ultrastructural alterations in oocytes (e.g., shrunken nuclei, narrower zona pellucida, decreased microvilli, lipid droplets, dispersed organelles) compared with controls. Apoptosis-related features were reported as more common in granulosa and corona radiata cells in exposed rats, with changes such as retraction, loss of microvilli, and mitochondrial cristae condensation/loss; authors suggest EMF exposure may interfere with folliculogenesis.

Outcomes measured

Ovarian follicle ultrastructure (TEM)
Apoptosis markers/morphology (TUNEL; apoptotic ultrastructural signs)
Folliculogenesis (inference from follicle changes)

Limitations

Frequency of the EMF is not reported in the abstract
Sample size not provided
Endpoints are primarily morphological/ultrastructural; functional fertility outcomes not reported
Exposure source/context (e.g., appliance type) not specified

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "4 h/day for 4 months"
  },
  "population": "Female Wistar rats (ovary/follicles)",
  "sample_size": null,
  "outcomes": [
    "Ovarian follicle ultrastructure (TEM)",
    "Apoptosis markers/morphology (TUNEL; apoptotic ultrastructural signs)",
    "Folliculogenesis (inference from follicle changes)"
  ],
  "main_findings": "Female Wistar rats exposed to a 3 mT low-frequency EMF for 4 h/day for 4 months showed ultrastructural alterations in oocytes (e.g., shrunken nuclei, narrower zona pellucida, decreased microvilli, lipid droplets, dispersed organelles) compared with controls. Apoptosis-related features were reported as more common in granulosa and corona radiata cells in exposed rats, with changes such as retraction, loss of microvilli, and mitochondrial cristae condensation/loss; authors suggest EMF exposure may interfere with folliculogenesis.",
  "effect_direction": "harm",
  "limitations": [
    "Frequency of the EMF is not reported in the abstract",
    "Sample size not provided",
    "Endpoints are primarily morphological/ultrastructural; functional fertility outcomes not reported",
    "Exposure source/context (e.g., appliance type) not specified"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF EMF",
    "3 mT",
    "rat",
    "Wistar",
    "ovary",
    "ovarian follicles",
    "granulosa cells",
    "apoptosis",
    "TUNEL",
    "transmission electron microscopy",
    "ultrastructure",
    "folliculogenesis"
  ],
  "suggested_hubs": [
    {
      "slug": "animal-studies",
      "weight": 0.9,
      "reason": "Experimental EMF exposure study in rats assessing ovarian follicle ultrastructure and apoptosis."
    }
  ]
}

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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: 10.3923/pjbs.2007.4413.4419
PubMed: 19093504

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