Effect of ultra‑wide‑band electromagnetic pulses on blood‑brain barrier permeability in rats

PAPER manual Mol Med Rep 2020 Animal study Effect: harm Evidence: Low

Read original paper → DOI: 10.3892/mmr.2020.11382 PMID: 32945403 Evidence Lab

Abstract

The restrictive nature of the blood brain barrier (BBB) brings a particular challenge to the treatment of central nervous system (CNS) disorders. The effect of ultra‑wide band electromagnetic pulses (UWB‑EMPs) on BBB permeability was examined in the present study in order to develop a safe and effective technology that opens the BBB to improve treatment options for CNS diseases. Rats were exposed to a single UWB‑EMP at various field strengths (50, 200 or 400 kV/m) and the BBB was examined using albumin immunohistochemistry and Evans blue staining at different time periods (0.5, 3, 6 and 24 h) after exposure. The expression and distribution of zonula occludens 1 (ZO‑1) were evaluated using western blotting to identify a potential mechanism underlying BBB permeability. The results showed that the BBB permeability of rats exposed to UWB‑EMP increased immediately following UWM‑EMP treatment and peaked between 3 and 6 h after UWB‑EMP exposure, returning to pre‑exposure levels 24 h later. The data suggested that UWB‑EMP at 200 and 400 kV/m could induce BBB opening, while 50 kV/m UWB‑EMP could not. The levels of ZO‑1 in the cerebral cortex were significantly decreased at 3 and 6 h after exposure; however, no change was observed in the distribution of ZO‑1. The present study indicated that UWB‑EMP‑induced BBB opening was field strength‑dependent and reversible. Decreased expression of ZO‑1 may be involved in the effect of UWB‑EMP on BBB permeability.

AI evidence extraction

At a glance

Study type

Animal study

Effect direction

harm

Population

Rats

Sample size

—

Exposure

microwave other · single ultra-wide-band electromagnetic pulse; assessed 0.5, 3, 6, and 24 h after exposure

Evidence strength

Low

Confidence: 92% · Peer-reviewed: yes

Main findings

In rats, BBB permeability increased immediately after ultra-wide-band electromagnetic pulse exposure, peaked at 3-6 h, and returned to baseline by 24 h. BBB opening was observed at 200 and 400 kV/m but not at 50 kV/m, and ZO-1 expression decreased at 3 and 6 h without an observed change in ZO-1 distribution.

Outcomes measured

Blood-brain barrier permeability
Albumin immunohistochemistry
Evans blue staining
ZO-1 expression in cerebral cortex
ZO-1 distribution

Limitations

Animal study
Sample size not stated in the abstract
Frequency not stated in the abstract
Exposure source/details beyond field strength not stated in the abstract

View raw extracted JSON

{
    "study_type": "animal",
    "exposure": {
        "band": "microwave",
        "source": "other",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "single ultra-wide-band electromagnetic pulse; assessed 0.5, 3, 6, and 24 h after exposure"
    },
    "population": "Rats",
    "sample_size": null,
    "outcomes": [
        "Blood-brain barrier permeability",
        "Albumin immunohistochemistry",
        "Evans blue staining",
        "ZO-1 expression in cerebral cortex",
        "ZO-1 distribution"
    ],
    "main_findings": "In rats, BBB permeability increased immediately after ultra-wide-band electromagnetic pulse exposure, peaked at 3-6 h, and returned to baseline by 24 h. BBB opening was observed at 200 and 400 kV/m but not at 50 kV/m, and ZO-1 expression decreased at 3 and 6 h without an observed change in ZO-1 distribution.",
    "effect_direction": "harm",
    "limitations": [
        "Animal study",
        "Sample size not stated in the abstract",
        "Frequency not stated in the abstract",
        "Exposure source/details beyond field strength not stated in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.92000000000000003996802888650563545525074005126953125,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "ultra-wide-band electromagnetic pulse",
        "UWB-EMP",
        "blood-brain barrier",
        "BBB permeability",
        "rats",
        "ZO-1",
        "Evans blue",
        "albumin immunohistochemistry",
        "field strength-dependent",
        "reversible effect"
    ],
    "suggested_hubs": []
}

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

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