Study type: Medical/biological study (experimental study)

Effects of esmolol on 35 GHz microwave-induced lethal heat stress. med./bio.

Published in: J Auton Pharmacol 1997; 17 (3): 165-173

Aim of study (acc. to author)

To examine effects of the β1-adrenoreceptor (beta-adrenergic receptors) antagonist esmolol on heart rate, blood pressure, respiratory rate, localized body temperature changes, survival times, and lethal body temperatures that occur during the exposure of anesthetized rats to 35 GHz microwaves. Anesthetized rats were exposed to 35 GHz microwaves at a level that resulted in heating and death.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 35 GHz
Modulation type: CW
Exposure duration: exposure was stopped when mean the arterial blood pressure dropped to 75 mmHg
Exposure 2: 35 GHz
Modulation type: CW
Exposure duration: until death

General information

More details on exposure set-up and conditions described in reference article.

Exposure 1

Main characteristics
Frequency 35 GHz
Type
Charakteristic
Exposure duration exposure was stopped when mean the arterial blood pressure dropped to 75 mmHg
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 13 mW/g mean - whole body -
power density 750 W/m² - - - -

Exposure 2

Main characteristics
Frequency 35 GHz
Type
Charakteristic
Exposure duration until death
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 13 mW/g mean - whole body -
power density 750 W/m² - - - -

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)

During exposure, a continuous increase in heart rate and a biphasic response in blood pressure (initial increase followed by a decrease) were revealed in all groups of rats. Esmolol caused a significant dose-dependent decrease in blood pressure, relative to saline-treated rats, but only a small attenuation of the heat-induced rise in heart rate.
In experiments in which esmolol was infused and irradiation was continued until death, drug-treated rats survived for significantly shorter periods and died at significantly lower body temperatures. The alteration in survival may have been related to the lower blood pressure due to esmolol treatment.

Study character:

Study funded by