Tri-ortho-cresyl phosphate induced neurotarget esterase inhibition in brain and peripheral nerve effectively monitored by lymphocytes.

Tri-ortho-cresyl phosphate ester (TOCP: 10-100 mg/kg)--an organophosphorus compound (OP) inhibited brain, peripheral nerve and lymphocyte neurotarget esterase activities in a dose related and time-dependent manner. There was a good correlation of inhibition between brain, peripheral nerve and lymphocyte tissues taken from adult hens treated with 3 different doses of TOCP and sacrificed 24 and 48 hr after exposure. The results suggest that lymphocyte can effectively monitor OP compounds for investigating inhibition of neurotarget esterase activity in brain and peripheral nerve tissues.

Effect of tri-ortho-cresyl phosphate on hen nervous system.

Correlation of tri-ortho-cresyl phosphate (TOCP) toxicity with clinical symptoms and inhibition patterns of neurotoxic esterase (NTE) in different regions of the central nervous system was studied in hens. The total content of NTE in spinal cord and peripheral nerves was relatively much lower than that of the brain, about 29 and 4.8 per cent respectively. Brain and spinal cord NTE was inhibited to 75 and 67 per cent respectively on day 1 post-TOCP treatment, and 91 and 84 per cent respectively on day 2, while the activity of the enzyme in peripheral nerve was inhibited to 92 per cent on day 1. However, the clinical manifestations of paralysis appeared after 7-8 days of TOCP treatment. It can be concluded that the presence of NTE in very low quantities in the peripheral nerves and its almost complete inhibition as compared to that of brain and spinal cord, could be of great significance in the development of neurotoxicity.