Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation.

Bioelectromagnetics · 1985 · No effect · Low evidence

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No effectLow evidencePaper 6190

Adult rats exposed for 30 min to 1.7-GHz continuous-wave or pulsed microwaves at 0.1 W/kg showed no change in uptake of either tracer in any measured brain region compared with sham-exposed animals.

Study snapshot

PublicationBioelectromagnetics · 1985

Study typeanimal

Reported directionNo effect

Evidence ratingLow

Abstract

The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [14C] sucrose and [3H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals.

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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 directionno_effect

PopulationAdult rats (anesthetized with pentobarbital)

Sample sizeNot supplied

Exposuremicrowave · 1700 MHz · 0.1 W/kg · 30 min

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Adult rats exposed for 30 min to 1.7-GHz continuous-wave or pulsed microwaves at 0.1 W/kg showed no change in uptake of either tracer in any measured brain region compared with sham-exposed animals.

Outcomes measured

Blood-brain barrier permeability (uptake of [14C] sucrose and [3H] inulin in brain regions)
Brain temperature in multiple regions during exposure

Limitations

Sample size not reported in abstract
Only one exposure duration (30 min) and SAR (0.1 W/kg) reported in abstract
Animal model; generalizability to humans not addressed in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "microwave",
    "source": null,
    "frequency_mhz": 1700,
    "sar_wkg": 0.1,
    "duration": "30 min"
  },
  "population": "Adult rats (anesthetized with pentobarbital)",
  "sample_size": null,
  "outcomes": [
    "Blood-brain barrier permeability (uptake of [14C] sucrose and [3H] inulin in brain regions)",
    "Brain temperature in multiple regions during exposure"
  ],
  "main_findings": "Adult rats exposed for 30 min to 1.7-GHz continuous-wave or pulsed microwaves at 0.1 W/kg showed no change in uptake of either tracer in any measured brain region compared with sham-exposed animals.",
  "effect_direction": "no_effect",
  "limitations": [
    "Sample size not reported in abstract",
    "Only one exposure duration (30 min) and SAR (0.1 W/kg) reported in abstract",
    "Animal model; generalizability to humans not addressed in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "blood-brain barrier",
    "BBB permeability",
    "rat",
    "microwave radiation",
    "1.7 GHz",
    "continuous-wave",
    "pulsed",
    "SAR 0.1 W/kg",
    "sucrose",
    "inulin",
    "brain temperature",
    "sham exposure"
  ],
  "suggested_hubs": []
}

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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: 10.1002/bem.2250060205
PubMed: 4004946

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