Document Detail

Characterization of phospholipase A2 activity in rat aorta smooth muscle cells.
MedLine Citation:
PMID:  6824708     Owner:  NLM     Status:  MEDLINE    
Phospholipase A activity was measured in homogenates and acid extracts of smooth muscle cells from rat aorta and mesenteric artery using [1-14 C]oleate-labeled autoclaved Escherichia coli and 1-[1-14C]stearyl-2-acyl-3-sn-glycerophosphorylethanolamine as substrates. The results demonstrate the presence of neutral-active phospholipase(s) A that exclusively catalyze the release of fatty acid from the 2-position of phospholipids. Optimal activity was at pH 7.5, and there was an absolute requirement for low concentrations of Ca2+. Mg2+ did not substitute for Ca2+, and EGTA inhibited the activity. Phospholipase A2 activity was predominantly membrane-associated and was solubilized by homogenization in 0.18 N H2SO4. Sulfuric acid extracts of rat aortic smooth muscle cells were four times more active than extracts of mesenteric artery (710 vs. 170 nmol/h per mg protein). By comparison, acid extracts of rat lung, heart, and liver were less active (60-75 nmol/h per mg). Indomethacin, sodium meclofenamate, mepacrine and chlorpromazine, but not dexamethasone or aspirin, inhibited acid-solubilized phospholipase(s) A2 between 10(-6) and 10(-3) M in a dose-dependent manner. Preincubation with p-bromophenacyl bromide or diethylpyrocarbonate inhibited phospholipase(s) A2, suggesting the presence of a histidine residue at the active site. An extract from the leaves of feverfew plant (Tanacetum parthenium) was also a potent inhibitor of aortic smooth muscle phospholipase(s) A2.
J K Thakkar; N Sperelakis; D Pang; R C Franson
Related Documents :
11100318 - Inhibited serum phospholipase a2 activity in hyperbilirubinemia.
10320808 - Evidence for two distinct lysophospholipase activities that degrade lysophosphatidylcho...
25244328 - Chemical dynamic kinetic resolution and s/r interconversion of unprotected α-amino acids.
3918038 - Cell cycle-dependent changes in arachidonic acid and glycerol metabolism in swiss 3t3 c...
8858128 - Reevaluation of superoxide scavenging activity of dihydrolipoic acid and its analogues ...
22170858 - Triterpene acids from rose hip powder inhibit self-antigen- and lps-induced cytokine pr...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  750     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  1983 Jan 
Date Detail:
Created Date:  1983-04-15     Completed Date:  1983-04-15     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  134-40     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Aorta / enzymology
Hydrogen-Ion Concentration
Liver / enzymology
Lung / enzymology
Mesenteric Arteries / enzymology
Muscle, Smooth, Vascular / enzymology*
Myocardium / enzymology
Organ Specificity
Phospholipases / metabolism*
Phospholipases A / metabolism*
Phospholipases A2
Plants, Medicinal
Tanacetum parthenium
Grant Support
Reg. No./Substance:
0/Sesquiterpenes; EC 3.1.-/Phospholipases; EC 3.1.1.-/Phospholipases A; EC A2

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Reversible alterations in fatty acid profile of glycerophospholipids in rat heart muscle induced by ...
Next Document:  Thermodynamics of steroid partitioning in dimyristoylphosphatidylcholine liposomes.