Study type: Medical/biological study (experimental study)

Altered Expression of Matrix Metalloproteinases and Tight Junction Proteins in Rats following PEMF-Induced BBB Permeability Change. med./bio.

Published in: Biomed Environ Sci 2012; 25 (2): 197-202

Aim of study (acc. to author)

To investigate protein expression alterations after inducing a change in the blood brain barrier permeability through pulsed electromagnetic fields (PEMF) in rats.

Background/further details

Protein expression and corresponding gene expression of occludin, ZO-1 and two metalloproteinases as well as the enzyme activity of the metalloproteinases were examined. Occludin is a transmembrane protein that restricts the permeability at the tight junctions. ZO-1 links transmembrane proteins to the actin cytoskeleton. A disruption of these combinations as well as an increased enzyme activity of metalloproteinases are associated with an increased permeability of the blood brain barrier.
Rats were sham exposed or exposed and analyzed 0.5, 1, 3, 6 or 12 hours post exposure (n=8 per group).

Endpoint

Exposure

Exposure Parameters
Exposure 1:
  • unspecified
Exposure duration: 200 seconds

Exposure 1

Main characteristics
Frequency
  • unspecified
Waveform
Exposure duration 200 seconds
Additional info 3.5 ns rising time, 14 ns pulse width, amplitude up to 200 kV, 1 Hz repetition rate
Exposure setup
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
electric field strength 200 kV/m - - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

The permeability of the blood brain barrier was significantly increased 0.5, 1 and 3 hours after exposure when compared to the sham exposed group. After exposure, protein expression and gene expression of occludin and ZO-1 were significantly decreased compared to the control group, while the expression of the metalloproteinases was significantly increased. Additionally, the enzyme activity of the metalloproteinases was significantly increased compared to the sham exposed group.
12 hours after the exposure, the values recovered and no changes in the permeability, protein expression, gene expression and enzyme activity were observed in comparison to the sham exposed group.
The authors conclude that PEMF exposure could transiently alter the permeabilty of the blood brain barrier and that this effect was related to modified expression levels of occludin, ZO-1 and metalloproteinases.

Study character:

Study funded by

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