Study type: Medical/biological study (experimental study)

Effects of neck exposure to 5.5 mT static magnetic field on pharmacologically modulated blood pressure in conscious rabbits med./bio.

By: Okano H, Ohkubo C
Published in: Bioelectromagnetics 2005; 26 (6): 469-480
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Aim of study (acc. to author)

To study the acute effects of local application of a static magnetic field to neck or pelvic region under pharmacologically modulated blood pressure; norepinephrine-induced hypertension as well as nicardipine (calcium channel blocker)-induced hypotension in conscious rabbits

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: 30 min

Exposure 1

Main characteristics
Frequency
Type
Exposure duration 30 min
Exposure setup
Exposure source
  • coil(s)
  • a pair of donut shaped annular electromagnets (33/24 cm outer/inner diameter, 2.8 cm thick)
Setup the rabbit was placed in a plastic cylinder holder (50 cm long, 16 cm inner diameter) which was placed into the pair of electromagnets. One electromagnet was located over the neck of the rabbit while the other one over the pelvis region.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 6.1 mT maximum measured - in the magnet und 4 mT in the center axis of the magnet
magnetic flux density 5.5 mT maximum measured - to 1 mT; in the neck or pelvis
magnetic flux density 4 mT maximum measured - in the head and ear
Additional parameter details

The estimated value of maximum magnetic gradient in the neck or pelvis was c.a 0.06 mT/mm and less than 0.04 mT/mm in the head and ear lobe.

Measurement and calculation details

The magnetic flux density in rz-plane within the inner peripheral surface of the magnet was measured using a gaussmeter.

Reference articles

  • Okano H et al. (2003): Anti-pressor effects of whole body exposure to static magnetic field on pharmacologically induced hypertension in conscious rabbits

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

Neck exposure significantly attenuated the pharmacologically induced vasoconstriction or vasodilation, and subsequently suppressed the increase or decrease in blood pressure compared with sham exposure. In contrast, pelvis exposure did not significantly antagonized norepinephrine-elevated blood pressure or nicardipine-reduced blood pressure.
The neck exposure had a biphasic and restorative effect on vascular tone and blood pressure acting to normalize the tone and blood pressure. The neck exposure caused a significant increase in baroreflex sensitivity in norepinephrine-elevated blood pressure compared with sham exposure.
The buffering effects of the static magnetic field on increased hemodynamic differences between norepinephrine-induced high vascular tone and nicardipine-induced low vascular tone might be, in part, dependent on baroreflex pathways, which could modulate norepinephrine-mediated response in conjunction with Ca2+ dynamics.

Study character:

Study funded by

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