Heparin-induced release of extracellular-superoxide dismutase form (V) to plasma.
Extracellular-superoxide dismutase [EC 1.15.1.1] (EC-SOD) is a secretory, tetrameric glycoprotein. A prominent feature of EC-SOD is its affinity for heparin. This enzyme in serum is heterogeneous with regard to heparin-affinity and can be divided into five fractions (I) to (V) by heparin-HPLC, whereas fibroblast-secreted EC-SOD consists mainly of form (V). An intravenous injection of 50 i.u. of heparin/kg body weight into two healthy volunteers led to an immediate rise of serum EC-SOD level by 2.4-2.8-fold. Only form (V), which was a minor component in pre-heparin serum, was increased by the intravenous injection. The half-life of serum EC-SOD after the prompt rise was about 90 min. The in vivo experiment using rats and an in vitro experiment strongly suggested the EC-SOD released into the plasma reconstituted the interaction with glycocalyx on the vascular endothelial cell surface in accordance with the elimination of heparin from the vascular system.
Adachi
T
T
Department of Pharmaceutics, Gifu Pharmaceutical University.
Yamada
H
H
Futenma
A
A
Kato
K
K
Hirano
K
K
D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008657:Metabolic Clearance Rate; D012685:Sepharose; D013482:Superoxide Dismutase / Q000097:blood* / Q000493:pharmacokinetics
D007527:Isoenzymes; D006493:Heparin; D012685:Sepharose; D013482:Superoxide Dismutase