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Titolo:
LIPOPROTEIN-ASSOCIATED PAF (LA-PAF) WAS FOUND IN WASHED HUMAN PLATELETS AND MONOCYTE MACROPHAGE-LIKE U937 CELLS/
Autore:
KORTH R; ZIMMERMANN K; RICHTER WO;
Indirizzi:
INSERM,U200,FIDA,FORSCH ALLGEMEINMED,PALESTRINASTR 7A D-80639 MUNICH GERMANY UNIV MUNICH,KLINIKUM GROSSHADERN,ZWEITE MED KLIN W-8000 MUNICH GERMANY
Titolo Testata:
Chemistry and physics of lipids
fascicolo: 2, volume: 70, anno: 1994,
pagine: 109 - 119
SICI:
0009-3084(1994)70:2<109:LP(WFI>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
LOW-DENSITY LIPOPROTEIN; ACTIVATING FACTOR PAF; HUMAN THROMBOCYTES; SEROTONIN RELEASE; ENDOTHELIAL-CELLS; ACETHER; RECEPTOR; BINDING; ACETYLHYDROLASE; CHOLESTEROL;
Keywords:
LIPOPROTEINS; LA-PAF; PAF RECEPTORS; HUMAN PLATELETS; MONOCYTES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
47
Recensione:
Indirizzi per estratti:
Citazione:
R. Korth et al., "LIPOPROTEIN-ASSOCIATED PAF (LA-PAF) WAS FOUND IN WASHED HUMAN PLATELETS AND MONOCYTE MACROPHAGE-LIKE U937 CELLS/", Chemistry and physics of lipids, 70(2), 1994, pp. 109-119

Abstract

Beyond cholesterol, inflammatory ether phospholipids such as platelet-activating factor (paf) may play a role in atherogenesis. (1) We detected a paf-like compound ('LA-paf') associated with human serum lipoproteins, mainly in LDL but not with the lipoprotein-poor fraction. (2) LA-paf was also found in washed human platelets, from where it was partially released during platelet aggregation in response to paf(50 nM) or thrombin (1 U). In addition, resident monocyte/macrophage-like U937cells carried huge amounts of LA-paf(41 ng per 10(7) cells) and metabolized added [H-3]paf to a labelled compound co-eluting with the retention time of LA-paf in standard HPLC. (3) Functionally, LA-paf had a comparable potency to synthetic paf, because LA-paf aggregated washed aspirin-treated platelets in a concentration-dependent manner. The specific paf receptor antagonist WEB2086 inhibited the platelet aggregation induced by three distinct LA-paf preparations as compared with synthetic paf with similar inhibitory concentrations (IC50: 35.6 +/- 12.8, 24.0 +/- 4.0, 38.0 +/- 15.8 nM for LA-paf, and 43.6 +/- 6.5 nM for synthetic paf), indicating that LA-paf interacted with paf receptors. (4)However, LA-paf had a distinct retention time using high-pressure liquid chromatography (HPLC) as compared with Synthetic paf. LA-paf eluted at 9-15 min and synthetic paf at 21-24 min. In addition, total and non-specific [H-3]paf binding to intact washed human platelets was affected differently by the two unlabelled agonists: while LA-paf increased total and non-specific (but not specific) binding in a significant manner (P <0.002 and P <0.007) as LDL did (P <0.006 and P <0.03), synthetic paf decreased total binding (P <0.03). Similarly, low-density lipoproteins (LDL) increased significantly the total [H-3]paf binding. Incontrast, paf did not affect specific [I-125]LDL binding to human fibroblasts. Our results show the presence of LA-paf in lipoproteins, washed human platelets and monocyte/macrophage-like cells. As LDL and LA-paf purified from the same LDL particles increased significantly the total [H-3]paf binding to intact human platelets, it might modulate platelet adherence to vascular endothelial cells.

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Documento generato il 02/04/20 alle ore 12:57:41