title: Release of a dynorphin A (1-8) degrading enzyme from the spinal cord by intraventricular morphine in the rat.
abstract: Intraventricular injection of morphine sulfate, 40 micrograms, released an enzyme from the spinal cord into the perfusate which degraded dynorphin A (1-8) and, to a lesser extent, dynorphin A (1-13) in urethane anesthetized rats. The enzyme did not degrade dynorphin A (1-17), Met-enkephalin, Leu-enkephalin, substance P and neurotensin. This dynorphin A (1-8) degrading enzyme was inhibited by aprotinin, thiorphan, and, to a lesser extent, by bacitracin but was not inhibited by bestatin. A kinetic study of the interaction between dynorphin A (1-8) and aprotinin with the enzyme indicated that it is competitive in nature. The pharmacological significance of the findings is still unknown.
mesh_terms: D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D001414:Bacitracin / Q000494:pharmacology; D001667:Binding, Competitive; D004399:Dynorphins / Q000378:metabolism*; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009479:Neuropeptides / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000187:drug effects / Q000201:enzymology*; D015244:Thiorphan; D008625:Tiopronin / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D009479:Neuropeptides; D010446:Peptide Fragments; D001414:Bacitracin; C026843:dynorphin (1-13); D004399:Dynorphins; C026770:dynorphin (1-8); D009020:Morphine; D007611:Aprotinin; D015244:Thiorphan; D008625:Tiopronin; D010447:Peptide Hydrolases