Study type: Medical/biological study (experimental study)

Microwave induced stimulation of 32Pi incorporation into phosphoinositides of rat brain synaptosomes. med./bio.

Published in: Radiat Environ Biophys 1989; 28 (3): 223-234

Aim of study (acc. to author)

To study the effect of microwave exposure on the metabolism of synaptosomal membrane phospholipids. 32Pi-incorporation into phosphoinositides was studied.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.8 GHz
Modulation type: pulsed
Exposure duration: 30 min

Exposure 1

Main characteristics
Frequency 2.8 GHz
Type
Exposure duration 30 min
Modulation
Modulation type pulsed
Pulse width 1 µs
Packets per second 1
Repetition frequency 350 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 2 m
Setup samples exposed in 16 x 100 mM glass tubes
Additional info distance between horn and samples : 2 m for PD 100 and 300 W/m² and 6 m for 10 W/m²
Parameters
Measurand Value Type Method Mass Remarks
power density 10 W/m² - cf. remarks - 100, 300 W/m²

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Irradiation of synaptosomes at a power density of 10 mW/cm² or more produced stimulation of the 32Pi-incorporation into phosphoinositides. The extent of 32Pi-incorporation was found to be much more pronounced in phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP2) as compared to phosphatidylinositol (PI) and phosphatidic acid (PA). Inclusion of 10 mM lithium (Li+) in the medium decreased the basal labeling of PIP2, PIP and PI and increased PA labeling. Li+ also inhibited the microwave stimulated PIP2, PIP and PI labeling but had no effect on PA labeling. Calcium ionophore (A23187) inhibited the basal and microwave stimulated 32Pi labeling of PIP and PIP2, stimulated basal labeling of PA and PI and had no effect on microwave stimulated PA and PI labeling. Calcium chelator (EGTA) on the other hand, had no effect on basal labeling of PA and PI, stimulated basal PIP and PIP2 labeling but did not change microwave stimulated labeling of these lipids. Microwave exposure did not produce any significant effect on the endogenous concentrations of the total as well as individual phospholipids of synaptosomes indicating that only phosphoinositide turnover was stimulated.

Study character:

Study funded by