The study was composed of two parts. In the first part, embryos in ovo (i.e. in the egg) at the stage of gastrula were divided into 3 groups (n=8-10 each): 1) exposure to the electromagnetic field, 2) co-exposure to the electromagnetic field and monochromatic red LED light, 3) a sham-exposed control group.
In the second part, a bovine erythrocyte solution and a homogenate of native 38-h quail embryo tissues were also either exposed to the electromagnetic field, co-exposed to the electromagnetic field and monochromatic red LED light or non-exposed as control groups in in vitro experiments.
Exposure duration: intermittent (48 s (c?) on/12 s off) for 158 hours
in ovo exposure
Exposure duration: continuous for 10 minutes
|Distance between exposed object and exposure source||3 cm|
|Chamber||eggs in plastic setup, later placed in incubator|
|Setup||a combination of a commercial 3G USB-modem (Huawei E173) and a commercial GSM 900 cellular phone (Nokia 3120) was used; the system was activated by a computer program; the modem was placed 3 cm over the eggs surface and the cell phone was placed 3 cm under the plastic setup for eggs; embryos were exposed for 120 h before the incubation at room temperature, afterwards the exposure was continued inside the incubator during the first 38 h of incubation|
|Sham exposure||A sham exposure was conducted.|
|Additional info||the co-exposure group was additionally exposed to red light from 20 single LED L7113PDC/H (λmax=630-650 nm); intermittent exposure was carried out for 180 s in total (60 s (c?) each time on the 2nd, 8th and 24th hour of each day during incubation) in the dark; the intensity of red light on the hatching egg surface was 0.1 mW/cm2; this LED exposure has been shown to be effective for stimulation of quail embryogenesis in an earlier study by the authors|
|Setup||one set of reaction mixtures for each enzyme (superoxide dismutase or catalase) was exposed to activated muted cell phone during the assay procedure|
|Additional info||the co-exposure group was additionally exposed to LED red light with 0.1 mW/cm2 intensity for 10 min|
|power density||0.25 µW/cm²||-||-||-||-|
In the in ovo tests, the formation of somites was significantly decreased in exposed embryos (group 1) compared to the control group (group 3). Co-exposure to red light and the electromagnetic field (group 2) did not show any differences compared to the control group. No malformations were detected in any group.
Lipid peroxidation was significantly increased and the catalase enzyme activity was significantly decreased in the exposure group compared to the control group. In the co-exposure group, lipid peroxidation was significantly decreased and the catalase enzyme activity was significantly increased compared to the exposure group.
In the in vitro experiments, the enzyme activities of superoxide dismutase and catalase were significantly decreased in exposed preparations compared to the control groups. In co-exposed preparations, both enzyme activities were significantly increased compared to the exposed preparations.
The authors conclude that exposure of Japanese quail embryos to a 900 MHz electromagnetic field (GSM) could induce oxidative stress. However, co-exposure to monochromatic red LED light might protect against this effect.