Premium
Metabolic and ionic requirements for the axoplasmic transport of dopamine β‐hydroxylase
Author(s) -
Garcia A. G.,
Kirpekar S. M.,
Prat J. C.,
Wakade A. R.
Publication year - 1974
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1974.sp010686
Subject(s) - chemistry , dinitrophenol , ouabain , axoplasmic transport , oligomycin , medicine , oxidative phosphorylation , sodium , endocrinology , atpase , biochemistry , enzyme , biology , anatomy , organic chemistry
1. Metabolic and ionic requirements for the intra‐axonal transport of dopamine β‐hydroxylase (DBH) were investigated in the cat hypogastric nerve‐inferior mesenteric ganglion preparation in vitro by monitoring the enzyme accumulation above a crush, 2‐2·5 cm distal to the ganglion. 2. DBH accumulation in the proximal segment immediately above the crush increased linearly up to 6 h, during incubation in normal Krebs solution at 37° C. The rate of transport of the enzyme was about 4 mm/h. 3. Removal of the ganglion, electrical stimulation or reserpine pretreatment (1–6 days before the experiment) did not modify the rate of DBH accumulation. 4. Anoxia and glucose deprivation, singly, did not affect accumulation of DBH; however, the combined treatment of anoxia plus glucose deprivation, or dinitrophenol plus glucose deprivation, very markedly interfered with accumulation. 5. Removal of sodium or potassium from Krebs solution markedly inhibited the transport of DBH. Preincubation of the nerve in a high‐calcium Krebs solution at 4° C, and then reincubation at 37° C, prevented the enzyme accumulation. 6. N ‐ethylmaleimide, ouabain and oligomycin markedly inhibited the transport of DBH. 7. The results suggest that transport of DBH, and therefore of noradrenaline storage vesicles, within the hypogastic nerve is dependent on metabolic energy derived from either glycolysis or oxidative phosphorylation. It is also suggested that the sodium‐potassium‐activated ATPase may play an important role in the intra‐axonal transport of storage vesicles.