Platelet-activating Factor Mediates Hydrogen Peroxide Induced Endothelial-leukocyte Adhesion
- VernacularTitle:血小板激活因子介导过氧化氢引起的白细胞-内皮细胞粘附
- Author:
Ziqiang DING
;
Shaohua LI
;
Zhongli WU
- Publication Type:Journal Article
- Keywords:
endothelial cells, vascular, platelet activating factor;
hydrogen peroxide;
leukocyte adhesion;
phospholipase A;
bovine
- From:
Academic Journal of Second Military Medical University
1982;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
The effects of hydrogen peroxide (H2O2) on endothelial-polymorphonuclear cells (EC-PMN) adhesion and their mechanisms wsre studied in cultured bovine pulmonary artery endothelial monolayers in vitro. H2O2 at various concentrations (10-1, 10-2, 10-3mol/L respectively) stimulated EC dependent PMN adhesion, of which l02mol/L H2O2 was the most potent one, increasing adhesion to 2.3 times that of the control. Pretreatment of PMNs with SRI 63-441, a platelet-activating factor (PAF) receptor antagonist, had no effect on H2O2 induced EC-PMN adhesion. Pretreatment of ECs with SRI 63-441 before H2O2 exposure significantly decreased PMN adherence to ECs. Pretreatment of ECs with phospholipase A2 inhibitor p-bromophenacyl-bromide or cahnodulin antagonist chlorpromazine and aildum ion chelate EGTA obviously decreased H2O2 induced increment of EC-PMN adhesion. These results suggest that H2O2 may activate ECs, causing the inflow of extracellular calcium or the release of calcium from intracellular deposits. Increased intracellular Ca2+ may bind with calmodulin to activate phospholipase A2 thus initiating PAF synthesis and promoting EC-PMN adhesion.
