Activity of phospholipase A2 in plasma increases in uremia

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Clinical Chemistry (Winston-Salem, North Carolina); (USA)

OSTI ID:6937886

Costello, J; Franson, R C; Landwehr, K; Landwehr, D M ^[1]

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1. Allegheny-Singer Research Institute, Pittsburgh, PA (USA)

We measured phospholipase A2 activity in normal and uremic plasma, using (1-{sup 14}C)oleate-labeled autoclaved Escherichia coli as substrate. Hydrolysis of bacterial phospholipid by crude plasma from both groups was optimal at pH 5.5, was specific for the 2-acyl position of phospholipids, and had an absolute requirement for calcium. Activity was greatest in the presence of added Ca{sup 2+}, 5 mmol/L, but this increase was inhibited by several divalent cations (Mg{sup 2+}, Zn{sup 2+}, Cu{sup 2+}, Ba{sup 2+}, Co{sup 2+}, Pb{sup 2+}, Fe{sup 2+}) and by Fe{sup 3+}. PLA2 activity was also inhibited by heparin at acid and alkaline pH, normal plasma being more sensitive than uremic plasma to this inhibition. Enzyme activity in undiluted plasma was eightfold greater in uremic than in normal plasma. Dilution of plasma by two to fourfold increased the total activity of both normal and uremic plasma. However, the relative differences in total activity between the groups remained constant (eight- to 11-fold). The cause and consequences of the increased PLA2 activity in uremia remain to be established.

• OSTI ID: 6937886
• Journal Information: Clinical Chemistry (Winston-Salem, North Carolina); (USA), Journal Name: Clinical Chemistry (Winston-Salem, North Carolina); (USA) Vol. 36:2; ISSN 0009-9147; ISSN CLCHA
• Country of Publication: United States
• Language: English

Related Subjects

550901* -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
BACTERIA
CALCIUM COMPOUNDS
CARBON 14 COMPOUNDS
CARBOXYLESTERASES
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
COUNTING TECHNIQUES
DISEASES
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
ESTERASES
ESTERS
HEMIC DISEASES
HYDROLASES
INHIBITION
IONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPASES
LIPIDS
METABOLISM
MICROORGANISMS
MONOCARBOXYLIC ACIDS
OLEIC ACID
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PATHOGENESIS
PHOSPHOLIPIDS
SCINTILLATION COUNTING
TRACER TECHNIQUES