Estradiol is a crucial factor involved in the regulation of the uterine activity and consequently important for fertility. Therefore, tissue from the endometrium and the myometrium was harvested from four sows during the mid-luteal cycle and placed in 24-well plates.
The frequency of 50 Hz was used because this is frequency is ubiquitous in Europe. The frequency of 120 Hz was found to effect cell cycle progression and cell viability and is also used in therapeutic applications. The magnetic flux density of 8 mT was used because this is a typical value occurring in industry and therapeutic equipment due to the authors.
|Chamber||tissue samples were exposed in a 24-well plate|
|Setup||well plates were placed in the magnetic field generator; temperature was continuously monitored and did not change during the experiment (37°C); gas composition was supplied to the incubation system and was constant during the experiment|
|Sham exposure||A sham exposure was conducted.|
|Additional info||non-exposed tissue samples were incubated at the same time as the exposed ones|
After 2 and 4 hours exposure to the 50 Hz magnetic field, the secretion of estradiol from endometrium tissue samples into the culture medium was significantly increased compared to the sham exposure. In contrast, after 2 hours exposure to the 120 Hz magnetic field, the estradiol level was significantly decreased when compared to the sham exposed tissue samples. In myometrium tissue samples, the secretion of estradiol into the culture medium was significantly increased after 4 hours exposure to the 50 Hz and to the 120 Hz magnetic field compared to the sham exposure. With progesterone added the only significant difference was an increase in 4 hours 120 Hz magnetic field exposed myometrium samples when compared to the sham exposed ones.
In the endometrium, the gene expression of CYP19A3 was significantly decreased after the 120 Hz magnetic field compared to the sham exposure while gene expression was significantly increased in the myometrium.
No significant difference was seen in the protein expression of P450 aromatase between exposed and sham exposed samples.
The authors conclude that extremely low frequency magnetic fields could influence the estradiol secretion and synthesis in porcine uterine tissue dependent on exposure duration and frequency and hypothesize that progesterone could potentially protect against these alterations.