Study type: Medical/biological study (experimental study)

Administration of a nitric oxide donor does not affect hypotension induced by 35-GHz microwave heating med./bio.

By: Ryan KL, Lovelace JD, Frei MR, Jauchem JR
Published in: Methods Find Exp Clin Pharmacol 1997; 19 (7): 455-464
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Aim of study (acc. to author)

To determine whether administration of S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, influences microwave-induced hypotension in anesthetized rats.

Background/further details

It was previously demonstrated that pressor responses to NO synthesis inhibition are reduced following 35 GHz microwave heating, implying that NO levels might also be reduced (publication 4499).
First, rats were irradiated until mean arterial pressure fell to 75 mmHg. Microwave irradiation was then discontinued and either SNAP or saline was infused.
In a second protocol, SNAP or saline was infused prior to and throughout microwave irradiation, which was continued until death.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 35 GHz
Modulation type: CW
Exposure duration: until the blood pressure decreased to 75 mmHg
Exposure 2: 35 GHz
Modulation type: CW
Exposure duration: until the death; 43.5 ± 2.6 min for Saline treated animals and 43.5 ± 1.9 min for SNAP treated animals

Exposure 1

Main characteristics
Frequency 35 GHz
Type
Charakteristic
Polarization
Exposure duration until the blood pressure decreased to 75 mmHg
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.1 m
Chamber Eccosorb RF-shielded anechoic chamber
Setup Rats placed on a Plexiglas holder in the chamber
Parameters
Measurand Value Type Method Mass Remarks
SAR 13 mW/g unspecified - whole body -
power density 750 W/m² unspecified measured - -

Exposure 2

Main characteristics
Frequency 35 GHz
Type
Charakteristic
Polarization
Exposure duration until the death; 43.5 ± 2.6 min for Saline treated animals and 43.5 ± 1.9 min for SNAP treated animals
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.1 m
Parameters
Measurand Value Type Method Mass Remarks
SAR 13 mW/g unspecified - whole body -
power density 750 W/m² unspecified measured - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

1) SNAP infusion affected neither the hypotension nor the survival time following microwave exposure.
2) SNAP infusion did not change either the onset or the magnitude of terminal hypotension.
Therefore, the authors conclude that exogenous NO does not affect cardiovascular responses to 35 GHz microwave heating.

Study character:

Study funded by

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