Svensjö E, Boschcov P, Ketelhuth D F J, Jancar S, Gidlund M
Laboratório de Imunologia Molecular, Instituto Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro.
Inflamm Res. 2003 May;52(5):215-20. doi: 10.1007/s000110300074.
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.
The hamster cheek pouch was prepared for intravital microscopy observations of macromolecular leakage at post capillary venules (=leaks) with FITC-dextran as tracer.
OxLDL (0.1 mg/ml), PAF (platelet activation factor, 50-100 nM) and protein fractions of oxLDL (10 microg/ml) were applied topically to hamster cheek pouches.
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.
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.
对氧化型低密度脂蛋白（oxLDL）以及通过oxLDL尺寸排阻色谱法获得的蛋白质组分进行检测，观察其局部应用于仓鼠颊囊时对血管通透性的影响。
制备仓鼠颊囊，以便通过活体显微镜观察以异硫氰酸荧光素标记的葡聚糖作为示踪剂时毛细血管后微静脉处的大分子渗漏（即渗漏点）。
将oxLDL（0.1 mg/ml）、血小板活化因子（PAF，50 - 100 nM）和oxLDL的蛋白质组分（10 μg/ml）局部应用于仓鼠颊囊。
应用oxLDL和PAF导致渗漏点数可逆性增加。PAF拮抗剂WEB 2170、L - 精氨酸甲酯（L - NAME）和一种β₂肾上腺素能受体激动剂几乎完全抑制（P<0.01）由oxLDL或PAF诱导的大分子渗漏。按毫克/毫升计算，发现蛋白质组分在诱导血浆渗漏方面比未分级的oxLDL更有效。
仓鼠oxLDL是仓鼠颊囊微循环中大分子渗漏增加的有效诱导剂。主要作用由LDL颗粒氧化产生的类PAF结构介导，但oxLDL还含有低分子量蛋白质，这些蛋白质可能有助于oxLDL增加血管通透性的总体效应。
