Effects of extremely low frequency electromagnetic fields on morphine analgesia and tolerance in rats.

General physiology and biophysics · 2017 · Benefit · Low evidence

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BenefitLow evidencePaper 4908

Rats exposed to a 50 Hz magnetic field showed significantly higher morphine analgesic effect compared with morphine-only rats (p < 0.05). In morphine-tolerant rats, magnetic-field exposure was associated with significantly higher analgesic effect than in morp…

Study snapshot

PublicationGeneral physiology and biophysics · 2017

Study typeanimal

Reported directionBenefit

Evidence ratingLow

Abstract

Several studies have demonstrated that the electromagnetic fields produce analgesic activity. The aim of this study was to investigate the effects of extremely low frequency (ELF) electromagnetic fields (EMF) on morphine analgesia and tolerance in rats. In the study, 78 adult male Wistar albino rats (approximately 240 ± 12 g) were used. The application of 50 Hz magnetic field, each day the same times for 30 minutes for 15 days, and a total of four times every 15 minute intervals. To constitute morphine tolerance, high dose of morphine (50 mg/kg) were administered for 3 days in rats and tolerance was evaluated on day 4. Prior to analgesia tests, the effective dose (5 mg/kg) of morphine was injected into rats. In the statistical analyzes of the data, analysis of variance (two-way ANOVA) was used and the multiple comparison determined by Tukey tests. The maximum analgesic effect of the 5 mT magnetic field was determined on 7 days. Administration of morphine (5 mg/kg) in rats exposed to a magnetic field, the analgesic effect was significantly higher compared to the morphine group (p < 0.05). Morphine tolerant animals exposed to a magnetic field, the analgesic effect was found significantly higher than morphine tolerant group rats (p < 0.05). Analgesia test data demonstrated that application of ELF-EMFs to rats increases the morphine analgesia and reduces morphine tolerance.

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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 directionbenefit

PopulationAdult male Wistar albino rats (~240 ± 12 g)

Sample size78

ExposureELF · 30 minutes/day for 15 days (50 Hz magnetic field; total of four times every 15-minute intervals each day)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

Morphine analgesic effect
Morphine tolerance (analgesic response in morphine-tolerant animals)

Limitations

Exposure details are incomplete in the abstract (e.g., how 5 mT relates to the 50 Hz exposure protocol and whether other field strengths were tested).
Analgesia/tolerance measurement methods are not described in the abstract.
Randomization, blinding, and control/sham exposure conditions are not described in the abstract.
Animal study; generalizability to humans is uncertain.

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 minutes/day for 15 days (50 Hz magnetic field; total of four times every 15-minute intervals each day)"
  },
  "population": "Adult male Wistar albino rats (~240 ± 12 g)",
  "sample_size": 78,
  "outcomes": [
    "Morphine analgesic effect",
    "Morphine tolerance (analgesic response in morphine-tolerant animals)"
  ],
  "main_findings": "Rats exposed to a 50 Hz magnetic field showed significantly higher morphine analgesic effect compared with morphine-only rats (p < 0.05). In morphine-tolerant rats, magnetic-field exposure was associated with significantly higher analgesic effect than in morphine-tolerant controls (p < 0.05), interpreted as reduced morphine tolerance.",
  "effect_direction": "benefit",
  "limitations": [
    "Exposure details are incomplete in the abstract (e.g., how 5 mT relates to the 50 Hz exposure protocol and whether other field strengths were tested).",
    "Analgesia/tolerance measurement methods are not described in the abstract.",
    "Randomization, blinding, and control/sham exposure conditions are not described in the abstract.",
    "Animal study; generalizability to humans is uncertain."
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF",
    "electromagnetic fields",
    "magnetic field",
    "50 Hz",
    "5 mT",
    "morphine",
    "analgesia",
    "tolerance",
    "rats",
    "Wistar"
  ],
  "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: 10.4149/gpb_2017008
PubMed: 28836499

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