抄録
The transport of dopamine β-hydroxylase (DBH) and tyrosine hydroxylase (TH) in guinea pig sciatic nerves was studied by measuring the accumulation of these enzyme activities to a ligature. Axonal flow of DBH protein in rat sciatic nerves was also studied by immunofluorescence, and the anatomical results were compared with the biochemical ones.
The DBH immunofluorescence was increased in the proximal 3-mm segment of a ligature up to 48 hr after ligation. The DBH activity was also highly accumulated in the proximal 3-mm segment until 48 hr after ligation. Retrograde axonal flow of DBH or TH was observed indouble ligation experiments at 5 hr after ligation, but at 24 hr the retrograde axonal flow apparently changed to the orthograde. The mean, or absolute axonal flow rate (mm/24 hr) of DBH in guinea pig sciatic nerves was 100, or 180, while that of TH was 20, or 32, respectively. The results suggest that DBH and TH may be localized in different intracellular compartments; DBH may be transported at a fast flow rate as a particulate enzyme, while TH at an intermediate flow rate mostly as a cytoplasmic enzyme.
