Expression of the water channel protein, aquaporin-4, in mouse brains exposed to mobile telephone radiofrequency fields.
Level 5 - mechanism / opinion, no new human data
Animal experiment (mechanism/bench research)
PubMed 19396718 · doi:10.1080/00313020902885045
What was done
Mice received 900 MHz far-field whole-body radiofrequency exposure at a specific absorption rate of 4 W/kg for either a single 60-minute acute session or 60 minutes/day, 5 days/week for 104 weeks. Controls were sham-exposed, freely mobile in cage (to control for restraint stress), or administered a clostridial toxin as a positive control known to induce microvascular endothelial injury and AQP-4 upregulation. Brains were perfusion-fixed with 4% paraformaldehyde, cut into coronal sections across six levels, and immunostained for aquaporin-4 (AQP-4).
What was found
The abstract reports no numerical data or statistical tests. Immunohistochemically detectable AQP-4 expression in mouse brains did not increase after acute (60 min) or chronic (104 weeks) radiofrequency exposure relative to sham or freely mobile controls. Positive control brains given clostridial toxin showed substantial upregulation of AQP-4.
Why it matters
The findings indicate that long-term and acute whole-body 900 MHz radiofrequency exposure does not alter AQP-4 expression in mice, suggesting no associated increase in blood-brain barrier permeability via this pathway.
Limits
Sample sizes were not reported in the abstract. Results are in mice and cannot be directly extrapolated to human health. Only a single frequency (900 MHz) and specific absorption rate (4 W/kg) were tested, and assessment was limited to immunohistochemical detection of AQP-4 rather than direct physiological measurement of blood-brain barrier integrity.
Cited by
- contradicts High levels of electromagnetic frequency (EMF) exposure disrupt aquaporins and shut down cellular fluid and nutrient transport.