Exposure to an Extremely-Low-Frequency Magnetic Field Stimulates Adrenal Steroidogenesis via Inhibition of Phosphodiesterase Activity in a Mouse Adrenal Cell Line.
Extremely low-frequency magnetic fields (ELF-MFs) are generated by power lines and household electrical devices. In the last several decades, some evidence has shown an association between ELF-MF exposure and depression and/or anxiety in epidemiological and animal studies. The mechanism underlying ELF-MF-induced depression is considered to involve adrenal steroidogenesis, which is triggered by ELF-MF exposure. However, how ELF-MFs stimulate adrenal steroidogenesis is controversial. In the current study, we investigated the effect of ELF-MF exposure on the mouse adrenal cortex-derived Y-1 cell line and the human adrenal cortex-derived H295R cell line to clarify whether the ELF-MF stimulates adrenal steroidogenesis directly. ELF-MF exposure was found to significantly stimulate adrenal steroidogenesis (p < 0.01-0.05) and the expression of adrenal steroid synthetic enzymes (p < 0.05) in Y-1 cells, but the effect was weak in H295R cells. Y-1 cells exposed to an ELF-MF showed significant decreases in phosphodiesterase activity (p < 0.05) and intracellular Ca2+ concentration (p < 0.01) and significant increases in intracellular cyclic adenosine monophosphate (cAMP) concentration (p < 0.001-0.05) and cAMP response element-binding protein phosphorylation (p < 0.05). The increase in cAMP was not inhibited by treatment with NF449, an inhibitor of the Gs alpha subunit of G protein. Our results suggest that ELF-MF exposure stimulates adrenal steroidogenesis via an increase in intracellular cAMP caused by the inhibition of phosphodiesterase activity in Y-1 cells. The same mechanism may trigger the increase in adrenal steroid secretion in mice observed in our previous study.
Institute of Liberal Arts and Sciences, Tokushima University, Tokushima, Japan.
Kazuyoshi
K
Kitaoka
Student Lab, Tokushima University Faculty of Medicine, Tokushima, Japan.
Shiyori
S
Kawata
Student Lab, Tokushima University Faculty of Medicine, Tokushima, Japan.
Tomohiro
T
Yoshida
Student Lab, Tokushima University Faculty of Medicine, Tokushima, Japan.
Fumiya
F
Kadoriku
Support Center for Advanced Medical Sciences, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
Mitsuo
M
Kitamura
D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000450:Aldosterone / Q000096:biosynthesis / Q000378:metabolism; D000818:Animals; D001557:Benzenesulfonates / Q000494:pharmacology; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003345:Corticosterone / Q000096:biosynthesis / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000096:biosynthesis / Q000378:metabolism; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D060526:Magnetic Fields; D051379:Mice; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013252:Steroid 11-beta-Hydroxylase / Q000235:genetics / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis*; D000098682:Steroidogenic Acute Regulatory Protein
C110258:4,4,',4'',4'''-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis(benzene-1,3-disulfonate); D001557:Benzenesulfonates; D017362:Cyclic AMP Response Element-Binding Protein; D010750:Phosphoproteins; D013256:Steroids; D000098682:Steroidogenic Acute Regulatory Protein; D000450:Aldosterone; D000242:Cyclic AMP; D013252:Steroid 11-beta-Hydroxylase; D010727:Phosphoric Diester Hydrolases; D002118:Calcium; D003345:Corticosterone; D006854:Hydrocortisone