scholarly journals Vitamin E Improves Microsomal Phospholipase A2 Activity and the Arachidonic Acid Cascade in Kidney of Diabetic Rats

2001 ◽  
Vol 131 (4) ◽  
pp. 1297-1301 ◽  
Author(s):  
Oh-Gye Kwag ◽  
Sung-Ok Kim ◽  
Jeong-Hwa Choi ◽  
In-Koo Rhee ◽  
Myung-Sook Choi ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Vitamin E ◽  
Phospholipase A2 ◽  
Diabetic Rats ◽  
Arachidonic Acid Cascade ◽  
Phospholipase A2 Activity

Arachidonic acid analogues as inhibitors of phospholipase A2 activity

1987 ◽  
Vol 15 (3) ◽  
pp. 418-419 ◽  
Author(s):  
KEITH A FOSTER ◽  
DEREK R. BUCKLE ◽  
KIM L. CRESCENZI ◽  
ASHLEY E. FENWICK ◽  
JOHN E. TAYLOR
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Phospholipase A2 Activity

scholarly journals The localization of phospholipase A2 in the secretory granule

1994 ◽  
Vol 300 (3) ◽  
pp. 619-622 ◽  
Author(s):  
S P Chock ◽  
E A Schmauder-Chock ◽  
E Cordella-Miele ◽  
L Miele ◽  
A B Mukherjee
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Secretory Granule ◽  
Secretory Granules ◽  
Lipid Mediator ◽  
Arachidonic Acid Cascade ◽  
Surface Receptors ◽  
The Matrix ◽  
Immunocytochemical Techniques ◽  
Granule Matrix

A heat-resistant phospholipase A2 has been detected in the secretory granules of the mast cell [Chock, Rhee, Tang and Schmauder-Chock (1991) Eur. J. Biochem. 195, 707-713]. By using ultrastructural immunocytochemical techniques, we have now localized this enzyme to the matrix of the secretory granule. Like the cyclo-oxygenase [Schmauder-Chock and Chock (1989) J. Histochem. Cytochem. 37, 1319-1328], this enzyme also adheres tightly to the ribbon-like granule matrix components. The results from Western-blot analysis suggest that it has a molecular mass of about 14 kDa. The localization of the phospholipase A2, the presence of a phospholipid store with millimolar concentrations of calcium and the localization of the enzymes of the arachidonic acid cascade make the secretory granule a natural site for lipid-mediator synthesis. The packaging of phospholipase A2, together with its substrate and the components of the arachidonic acid cascade, in the secretory granule represents a physical arrangement by which the initiation of the cascade and the release of mediators can be directly linked to the stimulation of cell-surface receptors.

The coumarin derivative AD6 inhibits the release of arachidonic acid by interfering with phospholipase A2 activity in human platelets stimulated with thrombin

1990 ◽  
Vol 29 (3-4) ◽  
pp. 364-373 ◽  
Author(s):  
S. Porcellati ◽  
V. Costantini ◽  
M. Prosdocimi ◽  
M. Stasi ◽  
R. Pistolesi ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Coumarin Derivative ◽  
Human Platelets ◽  
Phospholipase A2 Activity

Brain phospholipase A2-arachidonic acid cascade is involved in the activation of central sympatho-adrenomedullary outflow in rats

2000 ◽  
Vol 398 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Kunihiko Yokotani ◽  
Muchung Wang ◽  
Yoshinori Murakami ◽  
Shoshiro Okada ◽  
Masakazu Hirata
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Arachidonic Acid Cascade

Enhanced Phospholipase A2 Activity In Cholesterol-Enriched Platelets From Rabbits Fed A Cholesterol-Enriched Diet

1981 ◽  
Author(s):  
A J McLeod ◽  
M Johnson ◽  
K E Sucklino ◽  
P Walton
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Serum Cholesterol ◽  
Control Diet ◽  
Molar Ratio ◽  
Control Group ◽  
Pla2 Activity ◽  
Rate Limiting ◽  
Phospholipase A2 Activity

Phospholipase A2(PLA2) could be the rate-limiting enzyme in the metabolism of arachidonic acid (AA) derived from membrane phospholipid to thromboxane A2 (TXA2). Mal- ondialdehyde (MDA) production, which is considered to be an index of TXA2 synthesis, is increased in platelets which have been enriched in cholesterol by incubation with cholesterol-rich phospholipid dispersions in vitro.Rabbits were fed a diet supplemented with 0.5% w/w cholesterol for 4 weeks after which serum cholesterol was determined and the platelets examined and compared with rabbits fed a control diet. The cholesterol:phospholipid molar ratio (c/p) in the platelets, MDA production (stimulated by AA (imM) and basal) and PLA2 activity were estimated. PLA2 activity was estimated by measuring the % inversion by resuspended washed platelets of 1-acyl-2-(l- 14C)arachidonyl phosphatidylcholine to (1- 14C)arachidonic acid on stimulation with collagen (2μg/ml). Serum cholesterol in the cholesterol-fed group (n=9) was 488 ± 104 mg/ 100ml compared with the control group (n=3) which was 34 ± 4.7 mg/l00ml. Platelets from the cholesterol-fed rabbits showed a 20% increase in C/P (p<0.05); basal and AA stimulated MDA production was increased by 40% and 27% respectively compared with platelets from the control group. PLA2 activity was 1.26% conversion to products in the cholesterol-enriched platelets compared with 0.10% in the control platelets. This increase in activity was significant (p < 0.05).These results suggest that increased AA metabolism in cholesterol-enriched platelets may in part be due to increased PLA2 activity. This may reflect a physical effect of cholesterol on the platelet membrane predisposing arachidonyl phosphatidylcholine to PLA2 catalysed hydrolysis.

Interleukin-1beta stimulates phospholipase A2 activity in adult rat ventricular myocytes

1997 ◽  
Vol 272 (2) ◽  
pp. C450-C456 ◽  
Author(s):  
J. McHowat ◽  
S. Liu
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Ventricular Myocytes ◽  
Arachidonic Acid Release ◽  
Pla2 Activity ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
Acid Release ◽  
Cytosolic Pla2 ◽  
Phospholipase A2 Activity

We have examined whether interleukin (IL)-1beta modulates phospholipase A2 (PLA2) activity in ventricular myocytes. PLA2 activity was measured in isolated membrane and cytosol fractions with (16:0,[3H]18:1) plasmenylcholine and (16:0,[3H]18:1) phosphatidylcholine in the absence and presence of Ca2+. When measured in the absence of Ca2+ with plasmenylcholine, exposure to 5 ng/ml IL-1beta caused an increase in membrane-associated PLA2 activity for 10 min that returned to basal levels by 20 min. In the presence of Ca2+ with phosphatidylcholine, IL-1beta had no effect on membrane-associated PLA2 but decreased cytosolic PLA2 activity. Additionally, IL-1beta caused an increase in arachidonic acid release in 20 min. Pretreatment with E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one, a selective Ca2+-independent PLA2 inhibitor, blocked IL-1beta-induced increases in both PLA2 activity and arachidonic acid release. Exposure to IL-1 receptor antagonist (IL-1RA) alone had no effect on membrane-associated PLA2 activity. When incubated with IL-1beta, IL-1RA inhibited the IL-1beta-enhanced PLA2 activity. These results show that, via activation of its receptors, IL-1beta stimulates specifically membrane-associated Ca2+-independent plasmalogen-selective PLA2 in rat ventricular myocytes.

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