Dynorphin converting enzyme in the rat spinal cord. Decreased activities during acute phase of adjuvant induced arthritis.
This paper describes a study on a dynorphin converting enzyme in spinal cord homogenates from rats with experimental arthritis after adjuvant injection into one hindpaw. The enzyme resembles a neutral cysteine endopeptidase which cleaves the opioid peptide dynorphin B and generates its N-terminal fragment, Leu-enkephalin-Arg6 with opioid activity. It exhibits considerably lower activity against dynorphin A and alpha-neoendorphin, the two other prodynorphin derived peptides. The enzyme showed significantly higher activity in the dorsal part than in the ventral part of the spinal cord. A significant decrease in enzyme activity was observed in the dorsal spinal cord during inflammation as compared to vehicle-injected controls. This decrease paralleled a decrease in the tissue level of Leu-enkephalin-Arg6. These data thus indicate that adjuvant-induced arthritis may generate an important change in a converting enzyme acting on peptide structures, which may be involved in pain modulation. Therefore, a functional role of the present enzyme in the regulation of pain-related peptides is suggested.
Silberring
J
J
Department of Pharmacology, University of Uppsala, Sweden.
Sakurada
T
T
Nyberg
F
F
D000208:Acute Disease; D000595:Amino Acid Sequence; D000818:Animals; D001169:Arthritis, Experimental / Q000201:enzymology*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D008297:Male; D008969:Molecular Sequence Data; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013116:Spinal Cord / Q000201:enzymology*; D013379:Substrate Specificity
D012697:Serine Endopeptidases; C054870:dynorphin-converting endopeptidase