Rapid transport of noradrenaline in adrenergic axons of rat sciatic nerve distal to a crush.

The transport of NA in the rat sciatic nerve distal to a crush was studied in 5 mm segments. The disappearance of a NA fraction in consecutive segments with time after crushing (0-12 h) was interpreted to indicate a proximo-distal migration of a NA fraction into further distal parts of the nerve. This transportable NA fraction was found to be about 45% of the NA in normal sciatic nerves and migrated at a rate of approximately 8 mm/h. The apparently non-mobile fraction (55%) was probably mainly located in vaso-constrictor nerve terminals of the blood vessels supplying the nerve. This non-mobile NA fraction does not contribute to the NA accumulations proximal to a crush. Thus, when calculating the rate of transport of any substance from accumulation experiments, corrections for a non-mobile fraction must always be considered.