Increase of urinary extracellular-superoxide dismutase level correlated with cyclic adenosine monophosphate.
Extracellular superoxide dismutase (EC-SOD) is a secretory protein that is the major SOD isozyme in extracellular fluids. Plasma EC-SOD levels are distributed in two discrete groups with the rare group having an enzyme with glycine instead of arginine-213, which causes a 10-fold higher serum level. Within the common phenotype group, the urinary EC-SOD level was significantly correlated with the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), but not with serum EC-SOD. EC-SOD appears not to be leaked from the plasma by glomerular filtration, but rather to be secreted from the renal tubule or its surrounding tissues. The urinary EC-SOD level was also significantly correlated with the urinary cyclic adenosine monophosphate (cAMP) level. cAMP analogues and adenylate cyclase modulators significantly stimulated the expression of EC-SOD but not other SOD isozymes in cultured fibroblast cell lines. Moreover, injection of parathyroid hormone, in Ellsworth-Howard tests, increased urinary EC-SOD accompanied with the elevations of urinary cAMP and NAG. Together these observations suggest that factor(s) that stimulate the adenylate cyclase-cAMP system regulate the urinary EC-SOD level.
Adachi
T
T
Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, Japan. adachi@gifu-pu.ac.jp
Yamada
H
H
Hara
H
H
Futenma
A
A
Kakumu
S
S
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000118:Acetylglucosaminidase / Q000652:urine; D000255:Adenosine Triphosphate / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000652:urine*; D005110:Extracellular Space / Q000201:enzymology*; D005347:Fibroblasts; D006801:Humans; D007527:Isoenzymes / Q000652:urine; D007684:Kidney Tubules / Q000378:metabolism; D009154:Mutation; D010281:Parathyroid Hormone / Q000494:pharmacology; D010710:Phosphates / Q000652:urine; D011507:Proteinuria / Q000652:urine; D013482:Superoxide Dismutase / Q000097:blood / Q000652:urine*
D007527:Isoenzymes; D010281:Parathyroid Hormone; D010710:Phosphates; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D003994:Bucladesine; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D013482:Superoxide Dismutase; D000118:Acetylglucosaminidase; D015056:1-Methyl-3-isobutylxanthine