title: Axonal transport of puromycin-sensitive aminopeptidase in rat sciatic nerves.
abstract: Axonal transport of puromycin-sensitive aminopeptidase (PSA), a putative neuropeptide degrading-enzyme which removes amino acid residues from the amino-terminal of neuropeptides, was examined in the proximal, middle, and distal segments of rat sciatic nerves using a double-ligation technique. The soluble fraction of each segment was partially purified by MonoQ column chromatography, and showed two peaks of aminopeptidase activity. One of the aminopeptidases was PSA. At 48 h after the ligations, a significant amount of the axonal transport of PSA activity was found in the proximal segment. Western blot analysis of the segments also showed that immunoreactive PSA in the proximal segment was 2.1-fold higher than that in the middle segment. Furthermore, the immunohistochemical analysis of the segments showed an increase of the immunoreactive PSA in the proximal segment in comparison with the enzyme in the distal segment, indicating that PSA is mainly transported by anterograde axonal flow. These results suggest that PSA plays a role in the metabolism of neuropeptides in nerve terminals or synaptic clefts.
authors.affiliation: Laboratory of Natural Information Science, Graduate School of Integrated Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Chikuma
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Yajima
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hirano
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Katsuji
authors.initials: K
authors.lastname: Nishi
authors.forename: Iwao
authors.initials: I
authors.lastname: Ohkubo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kato
mesh_terms: D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology*; D015153:Blotting, Western; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D008297:Male; D011691:Puromycin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000201:enzymology* / Q000502:physiology; D020426:Sciatic Neuropathy / Q000201:enzymology
chemical_list: D000900:Anti-Bacterial Agents; D011691:Puromycin; D000626:Aminopeptidases; C025579:enkephalin degrading enzyme