Effects of a time varying strong magnetic field on release of cytosolic free Ca2+ from intracellular stores in cultured bovine adrenal chromaffin cells.
This study was made to explain the mechanisms for the effects of exposure to a time varying 1.51 T magnetic field on the intracellular Ca(2+) signaling pathway. The exposure inhibited an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine chromaffin cells induced by addition of bradykinin (BK) to a Ca(2+) free medium. The exposure did not change BK induced production of inositol 1,4,5-trisphosphate (IP(3)). [Ca(2+)](i) was markedly increased in IP(3) loaded cells, and this increase was inhibited by the magnetic field exposure. A similar increase in [Ca(2+)](i) by other drugs, which stimulated Ca(2+) release from intracellular Ca(2+) stores, was again inhibited by the same exposure. However, transmembrane Ca(2+) fluxes caused in the presence of thapsigargin were not inhibited by the magnetic field exposure in a Ca(2+) containing medium. Inhibition of the BK induced increase in [Ca(2+)](i) by the exposure for 30 min was mostly recovered 1 h after exposure ended. Our results reveal that the magnetic field exposure inhibits Ca(2+) release from intracellular Ca(2+) stores, but that BK bindings to BK receptors of the cell membrane and intracellular inositol IP(3) production are not influenced.
Ikehara
Toshitaka
T
Department of Physiology, School of Medicine, The University of Tokushima, Kuramoto-cho, Tokushima 770-8503, Japan.
Park
Ki Ho
KH
Yamaguchi
Hisao
H
Hosokawa
Keiko
K
Houchi
Hitoshi
H
Azuma
Mami
M
Minakuchi
Kazuo
K
Kashimoto
Hideki
H
Kitamura
Mitsuo
M
Kinouchi
Yohsuke
Y
Yoshizaki
Kazuo
K
Miyamoto
Hiroshi
H
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002477:Cells; D019439:Chromaffin Cells / Q000378:metabolism* / Q000528:radiation effects*; D004574:Electromagnetic Fields; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors
D015544:Inositol 1,4,5-Trisphosphate; D001920:Bradykinin; D002118:Calcium