NEUROTOXIC ACTIONS OF LAMBDA-CYHALOTHRIN ON RAT SCIATIC NERVE

Studies were made to evaluate in vivo effects of lambda-cyhalothrin (LCT, synthetic pyrethroid insecticide) on the compound motor action potential (CMAP), DNA methylation and ultrastructure of rat sciatic nerve fibers using electrophysiological, molecular and histological techniques. LCT was administered to adult female albino Wistar rats by gavage dose of 0.8, 3.06 and 6.12 mg/kg body weight (b.w.). The treatment was repeated at 48-h intervals for 13 days. LCT altered CMAP as compared with control group. Although the high dose of LCT (6.12 mg/kg b.w.) lowered the amplitude significantly, the two lower doses (0.8 and 3.06 mg/kg b.w.) had no significant effect on this parameter. However, these three doses decreased significantly the conduction velocity (p<0.05). In contrast, DNA methylation status was not affected. Furthermore, histological studies indicate that these doses induced both axon or myelin degeneration, myelin sheath separation and vacuolization in nerve fibers. The results suggest that LCT had a neurotoxic potential.