The effects of an electromagnetic field on the boundary tissue of the seminiferous tubules of the rat: A light and transmission electron microscope study.

Abstract

Human beings are unavoidably exposed to ambient electromagnetic fields (EMF) generated from various electrical devices and from power transmission lines. Controversy exists about the effects of EMF on various organs. One of the critical issues is that EMF may adversely affect the reproductive system. In order to examine this 30 rat pups were exposed to 50 Hz EMF (non-ionising radiation) during in utero development (approximately 3 weeks) and postnatal life (5 weeks). Groups of exposed rats were subsequently left in an environment free of EMF in order to observe recovery, if any, from the changes induced by EMF on the boundary tissue of the seminiferous tubules. The materials were processed and observed under a light and a transmission electron microscope. In the experimental rats boundary tissue was found disrupted at various layers. This tissue showed infoldings, which were perhaps due to the loss of collagen and reticular fibrils from the inner and outer non-cellular layers. The outer non-cellular layer, which was thinner than that of the control, was stripped away from the myoid cell layer in multiple regions, giving a "blister-like" appearance. The myoid cells showed fewer polyribosomes, pinocytotic vesicles and glycogen granules. Most mitochondria were found to lack cristae. The connections between individual myoid cells were apparently lost. There were signs of recovery in the boundary tissue following withdrawal from EMF exposure. These results suggest that EMF exposure may cause profound changes in the boundary tissue of the seminiferous tubules. Therefore exposure to EMF may result in pathological changes that lead to subfertility and infertility.

AI evidence extraction

Main findings

Thirty rat pups exposed to 50 Hz EMF during in utero development and postnatal life showed disruption of the boundary tissue of seminiferous tubules at various layers, including infoldings and thinning/stripping of the outer non-cellular layer with a "blister-like" appearance. Myoid cells showed fewer polyribosomes, pinocytotic vesicles and glycogen granules; many mitochondria lacked cristae; and connections between myoid cells were apparently lost. Signs of recovery were observed after withdrawal from EMF exposure.

Outcomes measured

• Histological/ultrastructural changes in boundary tissue of seminiferous tubules (light microscopy, transmission electron microscopy)
• Indicators of recovery after withdrawal from EMF exposure
• Reproductive pathology implications (subfertility/infertility suggested)

Limitations

• Exposure source/intensity metrics (e.g., field strength) not reported in the abstract
• No quantitative outcome measures or statistical analysis described in the abstract
• Fertility outcomes were not directly measured; infertility/subfertility is suggested based on tissue changes

Suggested hubs

• occupational-exposure (0.2)
  Mentions ambient EMF from electrical devices and power transmission lines, though the experiment is in rats and not explicitly occupational.

{
    "study_type": "animal",
    "exposure": {
        "band": "ELF",
        "source": null,
        "frequency_mhz": 0.05000000000000000277555756156289135105907917022705078125,
        "sar_wkg": null,
        "duration": "in utero (~3 weeks) plus postnatal (5 weeks); some groups withdrawn to observe recovery"
    },
    "population": "Rat pups (exposed during in utero development and postnatal life)",
    "sample_size": 30,
    "outcomes": [
        "Histological/ultrastructural changes in boundary tissue of seminiferous tubules (light microscopy, transmission electron microscopy)",
        "Indicators of recovery after withdrawal from EMF exposure",
        "Reproductive pathology implications (subfertility/infertility suggested)"
    ],
    "main_findings": "Thirty rat pups exposed to 50 Hz EMF during in utero development and postnatal life showed disruption of the boundary tissue of seminiferous tubules at various layers, including infoldings and thinning/stripping of the outer non-cellular layer with a \"blister-like\" appearance. Myoid cells showed fewer polyribosomes, pinocytotic vesicles and glycogen granules; many mitochondria lacked cristae; and connections between myoid cells were apparently lost. Signs of recovery were observed after withdrawal from EMF exposure.",
    "effect_direction": "harm",
    "limitations": [
        "Exposure source/intensity metrics (e.g., field strength) not reported in the abstract",
        "No quantitative outcome measures or statistical analysis described in the abstract",
        "Fertility outcomes were not directly measured; infertility/subfertility is suggested based on tissue changes"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "extremely low frequency",
        "ELF EMF",
        "50 Hz",
        "rat",
        "seminiferous tubules",
        "boundary tissue",
        "myoid cells",
        "testis",
        "light microscopy",
        "transmission electron microscopy",
        "recovery/withdrawal"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.200000000000000011102230246251565404236316680908203125,
            "reason": "Mentions ambient EMF from electrical devices and power transmission lines, though the experiment is in rats and not explicitly occupational."
        }
    ]
}

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