Increased microvascular permeability in the hamster cheek pouch induced by oxidized low density lipoprotein (oxLDL) and some fragmented apolipoprotein B proteins

Autor(es)

Svensjö‚ E. ; Boschcov‚ P. ; Ketelhuth‚ DFJ ; Jancar‚ S. ; Gidlund‚ M.

• Tipo de documento: Artigo Científico
• Fonte: Inflammation Research; v. 52, n. 5, p. 215-220, 2003.

Resumo

Objective and Design: Oxidized low-density lipoproteins (oxLDL) and protein fractions obtained by size exclusion chromatography of oxLDL were tested for vascular permeability effects on topical application to the hamster cheek pouch. Materials: The hamster cheek pouch was prepared for intravital microscopy observations of macromolecular leakage at post capillary venules (= leaks) with FITC-dextran as tracer. Treatment: OxLDL (0.1 mg/ml), PAF (platelet activation factor, 50-100 nM) and protein fractions of oxLDL (10 mug/ml) were applied topically to hamster cheek pouches. Results: Application of oxLDL and PAF resulted in reversible increases in the number of leaks. The PAF-antagonist WEB 2170, L-NAME and a beta(2)-adrenoceptor agonist inhibited (P < 0.01) almost completely the macromolecular leakage induced with oxLDL or PAF. Protein fractions were found to be more effective than unfractionated oxLDL in inducing plasma leakage as calculated on mg/ml-basis. Conclusion: Hamster oxLDL is a potent inducer of macromolecular leakage increase in the hamster cheek pouch microcirculation. The principal effect is mediated by PAF-like structures produced by the oxidation of the LDL-particle but oxLDL also contains low molecular weight proteins that could contribute to the overall vascular permeability increasing effect of ox LDL. (AU)

• Processo FAPESP: 99/00158-4 - Desenvolvimento de métodos para detectar a lipoproteína de baixa densidade oxidada (Ox LDL) com vários graus de modificações oxidativas e auto-anticorpos gerados contra a Ox LDL
• Beneficiário: Magnus Ake Gidlund
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 00/05327-8 - Consequências patológicas da ativação/inibição de leucócitos e sua modulação por mediadores lipídicos
• Beneficiário: Sônia Jancar
• Modalidade de apoio: Auxílio à Pesquisa - Temático