The effects of an acute and chronic exposure of mice to a 50 Hz magnetic field on the epidermal level of polyamines and ornithine decarboxylase enzyme activity should be investigated.
The level of polyamines is increased in cancerous tissues and ornithine decarboxylase generates polyamines, so these parameters were used as markers for skin tumorigenesis. Tumor data of the same study was published elsewhere (Kumlin et al. 1998).
Transgenic K2 mice, which show a 30-50 fold higher ornithine decarboxylase enzyme activity compared to wild type mice, were used together with wild type mice.
For acute exposure experiments, the following groups with wild type and transgenic mice each were used (n=6 each): 1) exposure to UV radiation, 2) exposure to the magnetic field, 3) sham exposure. For chronic exposure experiments, further groups with wild type and transgenic mice each were used (n=10 each): 4) exposure to UV radiation, 5) exposure to UV radiation and continuous magnetic field , 6) exposure to UV and intermittent magnetic field and 7) sham exposure.
| Exposure | Parameters |
|---|---|
|
Exposure 1:
50 Hz
Exposure duration:
continuous for 24 h
|
|
|
Exposure 2:
50 Hz
Exposure duration:
continuous for 10.5 months
continous chronic exposure
|
|
|
Exposure 3:
50 Hz
Exposure duration:
intermittend for 10.5 months
intermittend chronic exposure with various MF intensities
|
|
UV exposure groups received a single dose of 400 J/m² during acute exposure (group 1) and 200 J/m² for 35 min three times per week, respectively, during chronic exposure conditions (groups 4-6)
| Frequency | 50 Hz |
|---|---|
| Type | |
| Exposure duration | continuous for 24 h |
| Additional info | acute exposure |
| Exposure source |
|
|---|---|
| Chamber | polycarbonate cages |
| Setup | temperature and relative humidity were 23 ± 1°C and 50 ± 15%, respectively |
| Sham exposure | A sham exposure was conducted. |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | 100 µT | - | - | - | - |
| Frequency | 50 Hz |
|---|---|
| Type | |
| Exposure duration | continuous for 10.5 months |
| Additional info | continous chronic exposure |
| Exposure source |
|
|---|---|
| Sham exposure | A sham exposure was conducted. |
| Additional info | 50 Hz MF exposure of the sham-exposed group was less than 0.05 µT |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | - | - | - | - | not stated |
| Frequency | 50 Hz |
|---|---|
| Type | |
| Exposure duration | intermittend for 10.5 months |
| Additional info | intermittend chronic exposure with various MF intensities |
| Exposure source |
|
|---|---|
| Sham exposure | A sham exposure was conducted. |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | 1.3 µT | minimum | - | - | - |
| magnetic flux density | 13 µT | - | - | - | - |
| magnetic flux density | 130 µT | maximum | - | - | - |
In the acute exposure, a significant increase of the putrescine and spermidine levels was observed in transgenic mice exposed to the magnetic field (group 2) compared to sham exposed mice. In the same group, a significant decrease of the ornithine decarboxylase enzyme activity was spotted in transgenic mice compared to sham exposed mice. In wild type mice, no significant differences were found between the groups.
In wild type mice chronically exposed to UV radiation (group 4), a significant increase of the spermidine and spermine levels and a significant decrease of the putrescine level was observed compared to sham exposed mice. In transgenic mice, no significant differences were found between the groups. Moreover, no significant differences were found between groups co-exposed to UV radiation and a magnetic field (groups 5 and 6) and exposure to UV radiation alone.
The authors conclude that an acute exposure of mice to a 50 Hz magnetic field could affect the epidermal level of polyamines and ornithine decarboxylase enzyme activity and thus augment tumorigenesis.
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
