Axoplasmic transport and turnaround of neurotoxic esterase in hen sciatic nerve.
J Neurochem 1985; 44(2):616-621
The transport of neurotoxic esterase (NTE) was studied in the sciatic nerve of the White-leghorn-hen. Measurements were taken of the rate of accumulation of activity at either one or two ligations. NTE appeared to be transported down the sciatic nerve at a rate of 300 millimeters/day. Acetylcholinesterase was transported at a rate of about 500 millimeters/day. The movement of NTE between transport pools seemed sufficiently fast to warrant a model in which rates of exchange were included. The model uses exchange between anterograde, retrograde, and stationary pools to account for turnaround. The authors conclude that the ligation method does not appear to be sufficiently accurate for estimating the rates of NTE transport. However, they note that the data do indicate something of the nature of the proximo distal delay in the recovery of NTE activity following inhibition. While the transport rate appears fast enough for newly synthesized NTE to be transported to the most distal portions of the branches of the sciatic nerve from the cell body in less than 24 hours, a significant portion is dropped off and exchanged with the inhibited NTE in the retrograde and stationary pools. The further away from the cell body, the larger the dilution of the newly synthesized NTE in the anterograde mobile fraction, which may be important when considering susceptibility of longer axons to organophosphorus induced delayed neuropathy.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Neuropathology; Laboratory-animals; Organo-phosphorus-compounds; Enzyme-activity
Pharmacology Duke University Department of Pharmacology Durham, N C 27710
Journal of Neurochemistry
Duke University, Durham, North Carolina