Study type: Medical/biological study (experimental study)

Decreased plasma levels of nitric oxide metabolites, angiotensin II, and aldosterone in spontaneously hypertensive rats exposed to 5 mT static magnetic field. med./bio.

Published in: Bioelectromagnetics 2005; 26 (3): 161-172

Aim of study (acc. to author)

To evaluate at which magnetic flux density the exposure to static magnetic field suppresses and delays blood pressure elevation in spontaneously hypertensive rats.

Background/further details

The study was an attempt to partially replicate previous findings (publication 10200).

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: continuous for 12 weeks
Exposure 2:
Exposure duration: continuous for 12 weeks

General information

Rats divided into 3 groups (n=20/group) were treated under the following conditions: sham exposure with ip (interperitoneal) saline injection, exposure to 2 mT MF (magnetic field) with ip saline injection and exposure to 5 mT MF with ip saline injection

Exposure 1

Main characteristics
Frequency
Type
Exposure duration continuous for 12 weeks
Additional info Static magnetic field exposure
Exposure setup
Exposure source
  • a pair magnetic plates made of SrFe12O19
Chamber Transparent acrylic cage (40 cm long x 24 cm wide x 20 cm high) enclosed in paperboards avoiding the rats to see the magnetic plates.
Setup The rats head position throughout the experiment was in the range of ± 19 cm,± 8 cm, ±12 cm x,y,z respectively.
Additional info The exposure device (41 cm long x 29.6 cm wide x 16 cm high) composed of a pair of metal plates (41 cm long x 16 cm high x 0.6 cm or 1 cm diameter). The plates were attached to the outer walls of the cage. The mimimum distance between the inside of the magnetic plates was 26 cm and the magnetic field was attractive.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 550 µT mean measured - at the center of the cage; Bmax between 0.3 to 1 mT hence referred to as 1 mT field

Exposure 2

Main characteristics
Frequency
Type
Exposure duration continuous for 12 weeks
Additional info Static magnetic field exposure
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 2.8 mT mean measured - at the center of the cage; Bmax between 1.5 to 5 mT hence referred to as 5 mT field

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

The data showed that the exposure to static magnetic field at 5 mT, but not 1 mT, significantly suppressed and retarded the early stage development of hypertension for several weeks in spontaneously hypertensive rats compared with the age matched, sham exposed control animals. Exposure to 5 mT resulted in reduced plasma concentrations of nitric oxide metabolites together with lower levels of the hormones angiotensin II and aldosterone.
These results suggested that exposure to static magnetic field may suppress and delay the elevation of blood pressure via the nitric oxide pathways and hormonal regulatory systems.

Study character:

Study funded by

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