SUPEROXIDE DISMUTASE ACTIVITY (SOD) AND MALONDIALDEHYDE LEVEL (MDA) OF RAT EXPERIMENTAL COLON TUMOR TISSUES EXPOSED TO SINUSOIDAL MAGNETIC FIELD

摘要

We have investigated the effects of sinusoidal electromagnetic fields on superoxide dismutase activity and malondialdehyde level in an N-Methyl-N-nitrosourea induced colon tumor model.We used 28 male Wistar albino rats at the age of 2-2.5 months. The rats were classified into 4 groups: 1) N-Methyl-N-nitrosourea, 2) sinusoidal electromagnetic field -N-Methyl-N-nitrosourea , 3) sinusoidal electromagnetic field, and 4) control. After the 1st and 2nd groups were administered with N-Methyl-N-nitrosourea, the 2nd and 3rd groups were exposed to a sinusoidal magnetic field (50 Hz, 5 mT) for 6 h/day during 8 months. After the animals were sacrificed, MDA levels and SOD activities were determined in colon tissue homogenates. The data from all groups were statistically evaluated using Student's t-test and expressed as mean ± standard deviation derived from rats in each group.SOD activities (units/g tissue) and MDA levels (μmol/ g tissue) were found to be for group 1: 24.89±7.37 and 225.35±90.03; for group 2: 30.65±8.49 and 252.98±51.7; for group 3: 26.99+7.14 and 489.37±376.71; and for control: 26.19±4.51 and 126.48±4.25.Our studies demonstrated a statistically significant (p<0.05) increase in level of MDA, but differences were not statistically significant for SOD activities (p>0.05) in experimental groups compared to that of the control group.According to the findings of this study, sinusoidal magnetic field may increase the free radical levels, but antioxidant system may not have enough response under these circumstances.