[Effect of phenylmethylsulfonyl fluride pretreated on neurofilament subunits in spinal cords of hens administrated with tri-o-cresyl phosphate].

Abstract

To investigate the dynamic changes of neurofilaments (NFs) proteins in spinal cords of hens with phenylmethylsulfonyl fluride (PMSF) pretreatment for exploring the mechanism of tri-o-cresyl phosphate (TOCP)-induced delayed neuropathy (OPIDN).
Adult Roman hens were randomly divided into three groups, control, TOCP and PMSF + TOCP. Birds in PMSF + TOCP set were pretreated with PMSF, 24 hours later, hens in both TOCP group and PMSF + TOCP group were administrated with TOCP at a single dosage of 750 mg/kg. Then all animals were sacrificed on the corresponding time-points of 1, 5, 10, and 21 days respectively after dosing of 750 mg/kg TOCP. The spinal cords were dissected, homogenized, and centrifuged at 100,000 x g. The levels of high molecular neurofilament (NF-H), medium molecular neurofilament (NF-M) and low molecular neurofilament (NF-L) in both pellet and supernatant fractions of spinal cords were determined by SDS-PAGE and Western-blotting.
The hens in TOCP group showed paralysis gait at the end of 21-day experimental period. The levels of NFs proteins in spinal cords changed obviously. Compared with control, the NFs in pellet showed a dramatic decrease on day 10 and then followed by a recovery. In the supernatant, the NFs proteins showed similar changes, which decreased significantly on day 10 and almost recovered control on day 21. Such as, NF-L, NF-M and NF-H decreased by 51%, 86% and 38% on day10. The OPIDN signs were not observed in PMSF + TOCP group, and imbalances of NFs were obviously alleviated. Compared with control, only NF-M in pellet increased by 21% (P < 0.05) on day 21, others remained no changes; The levels of NF-H and NF-M in supernatant respectively increased by 19% and 35% on day 21, others were no significant statistical differences.
TOCP may induce imbalance of NFs levels in progress of OPIDN, and PMSF pretreatment may protect animals from OPIDN by reducing above changes, which may explain that TOCP-induced imbalance of NFs may be connected with the occurrence and development of OPIDN.