Effects of a time varying strong magnetic field on release of cytosolic free Ca2+ from intracellular stores in cultured bovine adrenal chromaffin cells.
ABSTRACT 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.
- SourceAvailable from: Guilherme Bertolino[Show abstract] [Hide abstract]
ABSTRACT: Abstract Purpose: Evaluate the effects of continuous magnetic field stimulation after four days of global encephalic ischemia on motor behavior and brain morphology in gerbils. Material and methods: Sixty Mongolian gerbils were divided into five groups: control (CG), sham (SG), ischemia (IG), ischemia north (INPG) and south (ISPG) pole. Experimental animals underwent bilateral occlusion of the carotid artery. In groups with magnetic stimulation, a 3200 gauss magnet was fixed to the skull. After brain perfusion, coronal sections of the striatum, motor cortex (M1) and CA1 area of the hippocampus (CA1) were cut and stained with hematoxylin and eosin. Results: In the open field test (OF) we observed an increase in crossing in the IG compared to the CG, INPG and ISPG (F=20.19), and a reduction in the time spent on the Rota-rod test (RR) with the IG compared to CG, IPNG and ISPG (F=17.59). Morphometric analysis revealed a reduction in the density of the neurons in the CA1, in the number of M1 and striatal neurons in the IG compared to the CG, INPG and ISPG. Conclusion: Our results demonstrate a potential therapeutic application of static magnetic fields for the preservation of motor behavior and neurons in regions analyzed after global cerebral ischemia.International Journal of Radiation Biology 03/2013; · 1.84 Impact Factor
- Gastroenterology 01/2011; 140(5). · 12.82 Impact Factor