Effect of Electromagnetic Field on Na+, K+-ATPase from Gills of Oreochromis mossambicus

The Na+, K+-ATPase (adenosine triphosphatase), the ion pump enzyme located in cell membrane, is a well-defined protein whose properties can be used to study the mechanism of electromagnetic field (EMF) interaction with biological system. Electromagnetic field of 60 Hz, and field strength of 10 kV/m was applied for 2 weeks on O. mossambicus to measure its effects on the Na+, K+-ATPase activity. The enzyme from gills showed a 30% decrease in the specific activity after exposure to EMF compared to the control ones. The ATPase specific activity of gills homogenate of post-exposed fish showed an increase (180%) over the directly affected ones after 2 weeks outside the field (late 1). No further increase in the specific activity of the enzyme for the fish kept 4 weeks outside the field (late 2). A change seen in enzyme activity was non-reversible (no return to normal value), when the pre-exposed fish were left outside the field for a period up to 4 weeks. It is concluded from this result that the applied field strength has an effect on Na+, K+-ATPase activity and aquatic environment has no shielding effect. Further research needed before establishing limits of exposure on human.