Exposure to 2.45 GHz radiofrequency modulates calcitonin-dependent activity and HSP-90 protein in parafollicular cells of rat thyroid gland

Tissue & cell · 2020 · Harm · Low evidence

← Research stream

HarmLow evidencePaper 1658

Study snapshot

PublicationTissue & cell · 2020

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Exposure to 2.45 GHz radiofrequency modulates calcitonin-dependent activity and HSP-90 protein in parafollicular cells of rat thyroid gland E López-Martín, F J Jorge-Barreiro, J L Relova-Quintero, A A Salas-Sánchez, F J Ares-Pena. Exposure to 2.45 GHz radiofrequency modulates calcitonin-dependent activity and HSP-90 protein in parafollicular cells of rat thyroid gland. Tissue Cell. 2020 Dec 26;68:101478. doi: 10.1016/j.tice.2020.101478. Highlights • Non-ionizing radiation could constitute a toxic environment, altering the morphology and functioning of parafollicular cells. • EMFs activate stress stimuli in the thyroid gland, which is associated with C-cell hyperplasia. • Non-ionizing radiation modulates expression of Heat Shock Protein 90 in calcitonin-positive cells. Abstract In this study we analyzed the response of parafollicular cells in rat thyroid gland after exposure to radiofrequency at 2.45 GHz using a subthermal experimental diathermy model. Forty-two Sprague Dawley rats, divided into two groups of 21 rats each, were individually exposed at 0 (control), 3 or 12 W in a Gigahertz Transverse Electro-Magnetic (GTEM) chamber for 30 min. After radiation, we used simple or fluorescence immunohistochemistry to measure calcitonin cells or cellular stress levels, indicated by the presence hyperplasia of parafollicular cells, heat shock protein (HSP) 90. Immunomarking of calcitonin-positive cells was statistically significant higher in the thyroid tissue of rats exposed to 2.45 GHz radiofrequency and cell hyperplasia appeared 90 min after radiation at the SAR levels studied. At the same time, co-localized expression of HSP-90 and calcitonin in parafollicular cells was statistically significant attenuated 90 min after radiation and remained statistically significantly low 24 h after radiation, even though parafollicular cell levels normalized. These facts indicate that subthermal radiofrequency (RF) at 2.45 GHz constitutes a negative external stress stimulus that alters the activity and homeostasis of parafollicular cells in the rat thyroid gland. However, further research is needed to determine if there is toxic action in human C cells. pubmed.ncbi.nlm.nih.gov

Machine Enhanced Logic

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

PopulationSprague Dawley rats

Sample size42

ExposureRF · 2450 MHz · 30 min (single exposure); outcomes assessed at ~90 min and 24 h post-exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Rats exposed to 2.45 GHz RF (3 or 12 W) showed statistically significantly higher immunomarking of calcitonin-positive cells in thyroid tissue, and parafollicular cell hyperplasia appeared 90 min after radiation at the studied SAR levels. Co-localized expression of HSP-90 and calcitonin in parafollicular cells was statistically significantly attenuated 90 min after radiation and remained significantly low at 24 h, even though parafollicular cell levels normalized.

Outcomes measured

Calcitonin-positive parafollicular (C) cell immunomarking
Parafollicular cell hyperplasia (as stress indicator)
HSP-90 expression/co-localization with calcitonin in parafollicular cells

Limitations

Subthermal experimental diathermy model; generalizability to typical human exposures not stated
SAR values not reported in abstract (only power levels 3 or 12 W)
Animal study; authors note uncertainty about relevance/toxic action in human C cells
Short follow-up (90 min and 24 h)

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": 2450,
    "sar_wkg": null,
    "duration": "30 min (single exposure); outcomes assessed at ~90 min and 24 h post-exposure"
  },
  "population": "Sprague Dawley rats",
  "sample_size": 42,
  "outcomes": [
    "Calcitonin-positive parafollicular (C) cell immunomarking",
    "Parafollicular cell hyperplasia (as stress indicator)",
    "HSP-90 expression/co-localization with calcitonin in parafollicular cells"
  ],
  "main_findings": "Rats exposed to 2.45 GHz RF (3 or 12 W) showed statistically significantly higher immunomarking of calcitonin-positive cells in thyroid tissue, and parafollicular cell hyperplasia appeared 90 min after radiation at the studied SAR levels. Co-localized expression of HSP-90 and calcitonin in parafollicular cells was statistically significantly attenuated 90 min after radiation and remained significantly low at 24 h, even though parafollicular cell levels normalized.",
  "effect_direction": "harm",
  "limitations": [
    "Subthermal experimental diathermy model; generalizability to typical human exposures not stated",
    "SAR values not reported in abstract (only power levels 3 or 12 W)",
    "Animal study; authors note uncertainty about relevance/toxic action in human C cells",
    "Short follow-up (90 min and 24 h)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "2.45 GHz",
    "radiofrequency",
    "RF",
    "subthermal",
    "diathermy",
    "GTEM chamber",
    "thyroid gland",
    "parafollicular cells",
    "C cells",
    "calcitonin",
    "HSP-90",
    "heat shock protein 90",
    "hyperplasia",
    "Sprague Dawley rat"
  ],
  "suggested_hubs": []
}

AI can be wrong. Always verify against the paper.

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: 10.1016/j.tice.2020.101478
PubMed: 33373917

Read the original paper →

Related papers

← Back to the Research Library