RESUMEN
<p><b>OBJECTIVE</b>To screen the differently expressed proteins related to regulating the depolymerization of microtubules in the spinal cord of hens exposed to tri-o-cresyl phosphate (TOCP) and to provide target protein evidence for exploring the mechanisms of the delayed neurotoxicology (OPIDN) induced by organophosphorus compounds (OPs).</p><p><b>METHODS</b>Forty two Roman hens were randomly divided into three groups, i.e. TOCP group treated with 1000 mg/kg TOCP; intervention group treated with 40 mg/kg phenylmethanesulfonyl fluoride (PMSF) before 1000 mg/kg TOCP treatment and control group treated with tap water. Four hens in each group were sacrificed on the 5th and 20th days after exposure, respectively. Spinal cords were separated and homogenates at low temperature, and the total proteins were extracted. The OPIDN symptoms observed and recorded in the remaining 6 hens in each group. The differently expressed proteins related to regulating the depolymerization of microtubules were screen by two-dimensional electrophoresis and mass spectroscopy (MS).</p><p><b>RESULTS</b>The OPIDN symptoms appeared on the 5th day after exposure in TOCP group, which were gradually serious with time. The results by two-dimensional electrophoresis and MS showed that the Stathmin expression was downregulated 3.4 times and 2.8 times in TOCP group, respectively, as compared with the control and PMSF intervention groups. However, there was no significant difference of the Stathmin expression between control group and PMSF intervention group.</p><p><b>CONCLUSION</b>The Stathmin expression in the spinal cord tissues of hens exposed to TOCP significantly downregulated. Moreover, the downregulated Stathmin expression may be related to excess polymerization of microtubules and the mechanism of OPIDN.</p>