Glycosylphosphatidylinositol-specific phospholipase D in blood serum: is the liver the only source of the enzyme?
In cases of systemic inflammatory response syndrome, sepsis, and septic shock, the activity of glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) in serum amounts to 20 to 25% of the activity found in a healthy control group. The activity of serum GPI-PLD is positively correlated with inflammatory markers and counts of monocytes and stab cells (bands) and negatively correlated with polymorphonuclear neutrophils and lymphocytes in severe diseases. This indicates a yet unknown involvement of the inflammatory system in GPI-PLD liberation and suggests that the liver is not the only source of the plasma enzyme. Plasma was shown to contain an effective inhibitor of GPI-PLD which is soluble in organic solvents. Its concentration in capillary plasma is 20-fold higher than in venous plasma. To find possible other sources of plasma GPI-PLD besides the liver, the GPI-degrading activity was measured in different organs of the rat. Product formation was analysed using [125I]TID-labeled GPI-AP.
Rhode
H
H
Institute of Biochemistry, Medical Faculty, Friedrich Schiller University, Jena, Germany. hrho@mti-n.uni-jena.de
Lopatta
E
E
Schulze
M
M
Pascual
C
C
Schulze
H P
HP
Schubert
K
K
Schubert
H
H
Reinhart
K
K
Horn
A
A
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D010739:Phospholipase D / Q000037:antagonists & inhibitors / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar; D013379:Substrate Specificity
D004791:Enzyme Inhibitors; D000469:Alkaline Phosphatase; D010739:Phospholipase D; C065017:glycoprotein phospholipase D