Machida M, Kameyama K, Asano G, Kumazaki T
Department of Pathology, Nippon Medical School, Tokyo, Japan.
Lab Invest. 1999 Jun;79(6):733-45.
Hematoporphyrin (HP) was used as a microenvironmental fluorescent probe to investigate the development of human atherosclerotic plaques. We compared the site of HP accumulation with changes in the HP fluorescence spectrum in atheromatous plaques and in a liposome control model, using a confocal laser scanning microscope equipped with a photonic multi-channel analyzer linked to a fluorescence spectrometer. Wavelength shifts of the two peaks of HP fluorescence (F1, 620 nm; and F2, 640-690 nm) were monitored, and the integrated F2/F1 ratio was calculated as a measure of HP fluorescence. The F1 peak is characteristic of a predominantly aqueous site. The ratio reflects selective changes in the distribution and overcrowding of HP molecules in the limited space of the artificial membrane model. Compared with a normal artery, the atherosclerotic lesions showed an increase in the area of HP fluorescence, increased fluorescence intensity, a red shift of the HP fluorescence spectrum, and an increased F2/F1 ratio. The F2/F1 ratio of the membranous structures was markedly greater in the cores of the fibrous plaques than in the other plaques. The F1 peak showed increased intensity in the atheromatous plaque core, whereas in hydrophilic fibrous regions, such as the cap of the plaque, the intensity of the F1 peak was lower than in the core region. HP aggregation was observed in damaged cells and in water surrounded by lipid in the atheromatous core. Using HP as a probe allowed us to determine not only the ionization or polarity of each region in the atherosclerotic plaques but also to detect the separation and fusion of the lipid bilayer or micelle lipids, as well as damage to the cellular membranes and cholesterol enrichment. These findings suggest that HP is useful for detecting clinically important changes in atherosclerotic lesions, to lipid-rich, unstable, and vulnerable plaques, which are closely associated with cardiovascular events.
血卟啉（HP）被用作微环境荧光探针来研究人类动脉粥样硬化斑块的发展。我们使用配备了与荧光光谱仪相连的光子多通道分析仪的共聚焦激光扫描显微镜，比较了HP在动脉粥样硬化斑块和脂质体对照模型中的积累部位以及HP荧光光谱的变化。监测HP荧光两个峰（F1，620nm；F2，640 - 690nm）的波长偏移，并计算积分F2/F1比值作为HP荧光的度量。F1峰是主要为水相部位的特征峰。该比值反映了人工膜模型有限空间内HP分子分布和拥挤程度的选择性变化。与正常动脉相比，动脉粥样硬化病变显示HP荧光面积增加、荧光强度增强、HP荧光光谱红移以及F2/F1比值增加。纤维斑块核心处膜结构的F2/F1比值明显高于其他斑块。F1峰在动脉粥样硬化斑块核心处强度增加，而在亲水性纤维区域，如斑块帽，F1峰强度低于核心区域。在动脉粥样硬化核心受损细胞和脂质包围的水中观察到HP聚集。使用HP作为探针不仅使我们能够确定动脉粥样硬化斑块中每个区域的离子化或极性，还能检测脂质双层或胶束脂质的分离和融合，以及细胞膜损伤和胆固醇富集。这些发现表明，HP可用于检测动脉粥样硬化病变中临床上重要的变化，针对富含脂质、不稳定且易损的斑块，这些斑块与心血管事件密切相关。
