The effect of pulsed electromagnetic fields on the physiologic behaviour of a human astrocytoma cell line.
We evaluated the effects of 50 Hz pulsed electromagnetic fields (EMFs) with a peak magnetic field of 3 mT on human astrocytoma cells. Our results clearly demonstrate that, after the cells were exposed to EMFs for 24 h, the basal [Ca(2+)](i) levels increased significantly from 124+/-51 nM to 200+/-79 nM. Pretreatment of the cells with 1.2 microM substance P increased the [Ca(2+)](i) to 555+/-278 nM, while EMF exposure caused a significant drop in [Ca(2+)](i) to 327+/-146 nM. The overall effect of EMFs probably depends on the prevailing Ca(2+) conditions of the cells. After exposure, the proliferative responses of both normal and substance P-pretreated cells increased slightly from 1.03 to 1.07 and 1.04 to 1.06, respectively. U-373 MG cells spontaneously released about 10 pg/ml of interleukin-6 which was significantly increased after the addition of substance P. Moreover, immediately after EMF exposure and 24 h thereafter, the interleukin-6 levels were more elevated (about 40%) than in controls. On the whole, our data suggest that, by changing the properties of cell membranes, EMFs can influence Ca(2+) transport processes and hence Ca(2+) homeostasis. The increased levels of interleukin-6 after 24 h of EMF exposure may confirm the complex connection between Ca(2+) levels, substance P and the cytokine network.
Aldinucci
C
C
Palmi
M
M
Sgaragli
G
G
Benocci
A
A
Meini
A
A
Pessina
F
F
Pessina
G P
GP
D001254:Astrocytoma; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000528:radiation effects; D004574:Electromagnetic Fields; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects / Q000378:metabolism; D013373:Substance P / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*
D015850:Interleukin-6; D019837:Ryanodine Receptor Calcium Release Channel; D013373:Substance P; D002110:Caffeine; D002118:Calcium