Effects of physical stimulation with electromagnetic field and insulin growth factor-I treatment on proteoglycan synthesis of bovine articular cartilage.

Osteoarthritis and cartilage · 2004 · Benefit · Low evidence

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BenefitLow evidencePaper 5216

Study snapshot

PublicationOsteoarthritis and cartilage · 2004

Study typein_vitro

Reported directionBenefit

Evidence ratingLow

Abstract

OBJECTIVE: To investigate the single and combined effects of electromagnetic field (EMF) exposure and the insulin growth factor-I (IGF-I) on proteoglycan (PG) synthesis of bovine articular cartilage explants and chondrocytes cultured in monolayers. DESIGN: Bovine articular cartilage explants and chondrocyte monolayers were exposed to EMF (75Hz; 1.5mT) for 24h in the absence and in the presence of both 10% fetal bovine serum (FBS) and IGF-I (1-100ng/ml). PG synthesis was determined by Na(2)-(35)SO(4) incorporation. PG release into culture medium was determined by the dimethylmethylene blue (DMMB) assay. RESULTS: In cartilage explants, EMF significantly increased (35)S-sulfate incorporation both in the absence and in the presence of 10% FBS. Similarly, IGF-I increased (35)S-sulfate incorporation in a dose-dependent manner both in 0% and 10% FBS. At all doses of IGF-I, the combined effects of the two stimuli resulted additive. No effect was observed on medium PG release. Also in chondrocyte monolayers, IGF-I stimulated (35)S-sulfate incorporation in a dose-dependent manner, both in 0% and 10% FBS, however, this was not modified by EMF exposure. CONCLUSIONS: The results of this study show that EMF can act in concert with IGF-I in stimulating PG synthesis in bovine articular cartilage explants. As this effect is not maintained in chondrocyte monolayers, the native cell-matrix interactions in the tissue may be fundamental in driving the EMF effects. These data suggest that in vivo the combination of both EMF and IGF may exert a more chondroprotective effect than either treatment alone on articular cartilage.

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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 typein_vitro

Effect directionbenefit

PopulationBovine articular cartilage explants and bovine chondrocytes cultured in monolayers

Sample sizeNot supplied

ExposureELF · 24 h

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Bovine cartilage explants exposed to EMF (75 Hz; 1.5 mT) for 24 h showed significantly increased 35S-sulfate incorporation (PG synthesis) in both 0% and 10% fetal bovine serum conditions. IGF-I increased 35S-sulfate incorporation dose-dependently, and combined EMF+IGF-I effects were additive at all IGF-I doses; no effect was observed on PG release into the medium. In chondrocyte monolayers, IGF-I increased 35S-sulfate incorporation dose-dependently, but this was not modified by EMF exposure.

Outcomes measured

Proteoglycan (PG) synthesis (Na2-35SO4 incorporation)
PG release into culture medium (DMMB assay)

Limitations

Sample size not reported in abstract
In vitro bovine explants/monolayers; generalizability to in vivo or humans not established
Only one EMF condition reported (75 Hz; 1.5 mT; 24 h)

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": "ELF",
    "source": "laboratory EMF exposure",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "24 h"
  },
  "population": "Bovine articular cartilage explants and bovine chondrocytes cultured in monolayers",
  "sample_size": null,
  "outcomes": [
    "Proteoglycan (PG) synthesis (Na2-35SO4 incorporation)",
    "PG release into culture medium (DMMB assay)"
  ],
  "main_findings": "Bovine cartilage explants exposed to EMF (75 Hz; 1.5 mT) for 24 h showed significantly increased 35S-sulfate incorporation (PG synthesis) in both 0% and 10% fetal bovine serum conditions. IGF-I increased 35S-sulfate incorporation dose-dependently, and combined EMF+IGF-I effects were additive at all IGF-I doses; no effect was observed on PG release into the medium. In chondrocyte monolayers, IGF-I increased 35S-sulfate incorporation dose-dependently, but this was not modified by EMF exposure.",
  "effect_direction": "benefit",
  "limitations": [
    "Sample size not reported in abstract",
    "In vitro bovine explants/monolayers; generalizability to in vivo or humans not established",
    "Only one EMF condition reported (75 Hz; 1.5 mT; 24 h)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "electromagnetic field",
    "ELF",
    "75 Hz",
    "1.5 mT",
    "IGF-I",
    "proteoglycan synthesis",
    "articular cartilage",
    "chondrocytes",
    "bovine",
    "35S-sulfate incorporation",
    "DMMB"
  ],
  "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: 10.1016/j.joca.2004.06.012
PubMed: 15450529

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