Scanning electron microscopic studies on the route of neutrophil extravasation in the mouse after exposure to the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP)
Scanning electron microscopic studies on the route of neutrophil extravasation in the mouse after exposure to the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP)
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DOI：
10.1679/aohc.62.253
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发表时间：
1999-08-01
影响因子：
--
通讯作者：
Ushiki, T
中科院分区：
文献类型：
--
作者：
Hoshi, O;Ushiki, T
本研究旨在三维展示泥沼中细菌趋化肽 N-甲酰基-甲硫氨酰-亮氨酰-苯丙氨酸 (fMLP) 诱导的中性粒细胞外渗过程。将 fMLP 注射到小鼠唇部 30 至 40 分钟后，用戊二醛固定组织，并通过扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 进行检查。对注射fMLP的组织的观察显示，许多中性粒细胞粘附在毛细血管后微静脉的内壁上。其中一些粘附的中性粒细胞彼此附着，形成两到六个的群体。还有许多中性粒细胞穿过内皮细胞迁移。大多数中性粒细胞采用跨细胞途径，即穿透内皮细胞的细胞质。两个相邻内皮细胞的连接处没有打开，并且几乎观察不到没有迁移的中性粒细胞的内皮孔。血管壁上有凸起部分，这可能是由于下层中性粒细胞的存在而产生的。因此，本研究提供了中性粒细胞响应 fMLP 通过跨细胞途径迁移的直接证据。我们的研究结果还表明，中性粒细胞外渗后，内皮细胞的孔迅速闭合。
The present study was performed to demonstrate three-dimensionally the process of neutrophil extravasation induced by the bacterial chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) in mire. Thirty to 40 min after the injection of fMLP to the mouse lip, the tissues were fixed with glutaraldehyde and examined by scanning electron microscopy (SEM) as well as by transmission electron microscopy (TEM). Observation of fMLP-injected tissues showed many neutrophils adhering to the inner wall of postcapillary venules. Some of these adherent neutrophils attached to each other to form groups of two to six. There were also many neutrophils migrating through the endothelium. Most of these neutrophils took a transcellular route, in that they penetrated the cytoplasm of the endothelial cells. The junction of two neighboring endothelial cells did not open, and endothelial pores free from migrating neutrophils were scarcely observed. There were bulging portions on the vascular wall which were probably produced by the presence of underlayed neutrophils. Thus, the present study gave direct evidence of neutrophil migration via a transcellular route in response to fMLP. Our findings also indicate that the pores of the endothelium close quickly after neutrophil extravasation.