Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2002.931.937AttiaAzza A.YehiaMona A.9200259The effect of low frequency electromagnetic field (EMF) of 50 Hz at flux density of 100 μT on the immune system and liver tissues of mice was tested. The mice were exposed to short (10 and 20 days) and long (50 days) time of exposure. The long time exposure (50 days) of the magnetic field affected greatly all tissues more than those of short time (10 and 20 days). Histologically, during the exposure time of the experiment, spleen and liver tissues were more affected than thymus tissue. Destruction in spleen and liver sections were observed. Ultrastructural observations of the liver hepatocytes revealed highly irregular nuclei, autolyzed chromatin and most of the mitochondria were degenerated and had lost their cristae. Moreover, megakaryocytes were scattered in most spleen sections. Thymus tissue revealed a decrease in cell population of the medullary areas and showed the presence of certain pyknosis in most cortical regions. The immunohistochemical studies showed a gradual decrease in the enzymatic activity of glutathion-S- transferase (GST-p) of experimental mice group with the increase in the duration of the exposure time indicating the inability of spleen and liver tissues to protect themselves. However, thymus tissue showed a proportional increase in the enzymatic activity with the increase of the time of exposure to the EMF indicating its reactivity.]]>Cadossi, R., F. Bersani, A. Cassarizza, P. zucchini, G. Emilia, G. Torelli and C. Francechi,1992626672674Capri, M.,19991999pp: 195-198pp: 195-198Feinendegen, L.E. and H. Muhlensiepen,198812119123 Benquet, C. and P. Roux,1998+2 and functional alterations in lymphocytes and macrophages after in vitro exposure to static magnetic field.]]>546376Gorczynska, E. and R. Wegrzynowicz,199155188198Hsu, S.M., L. Reine and H. Fange,198124577580Huppertz, B., H.G. Frank and P. Kaufmann,1999200118Kamel, O.W., D.P. Le Brun, G.J. Berry, R.F. Dorfman and R.A. Warnke,199297179183Liburdy, R.P.,1995293035Marino, A.A., R.M. Wolcott, R. Chervenak, F. Jourd-Heuit, E. Nilson and C. Frilot,2000279761768Mannervik, B.,198557357417Mevissen, M., M. Lerchl, M. Szamel and W. Loscher,199617903910Mevissen, M., M. Haussler, M. Szamel, S.E. Thun-Battersby and W. Loscher,1998in vivo on immune functions in female Sprague dawley rats.]]>19259270Mohamed, M.M., A.A. Attia and T.E. Shalby,200073145Quaglino, D.,20009267982Reynolds, E.S.,196317208212Rosen, A.D. and J. Lubowsky,198795679687Rudolph, K., A. Wirtz-Justice, K. Krauchi and H. Feer,1988446159160Rusovan, A. and M. Kanje,19922+ antagonist, prevents simulation of nerve regeneration by magnetic field.]]>3314318Sagan, L.A.,1992268625629Thun-Battersby, S., J. Westermann and W. Loscher,1999152436443Trembly, L., G. Houde, J. Mercier and R. Mandeville,199617373383Urban, J.L. and H. Schreiber,19881988pp: 17-68pp: 17-68Voyedovodskaya, N.V., D.S. Burbayev and L.A. Blyumenfeld,19812615Walleczek, J.,1992631773185Wheater, P.R., H.G. Burkitt and V.G. Daniels,1993pp: 40pp: 40