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Ultrastructural transition from the elastic to the muscular arteries

从弹性动脉到肌性动脉的超微结构转变

基本信息

批准号：
06670038
负责人：
SASAKI Tatsuo
金额：
$ 1.22万
依托单位：
Juntendo University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The distribution of actin filaments (AFs) in the endothelial cells was compared between in the aorta (elastic artery) and in the intrarenal arteries (muscular artery). In the adult rats, the distributional patterns of endothelial AFs in these arterial segments were almost identical. On the contrary, AFs in the aortic endothelial cells were shown to be reorganized from the stress fibers at birth to the peripheral bands in the adult. The subendothelial basement membranes of the intrarenal arteries showed the ultrastructural heterogeneity along the course of the arterial tree.For the comparison of the medial ultrastructure between elastic and muscular arteries, we studied the intrapulmonary arteries, where the transition of the two types of arteries could be traced within the lung. It was revealed that the transition occurs abruptly in the lung without any intermediary segment. An immunocytochemical study on the myosin heavy chain isoforms revealed a molecular heterogeneity between the renal glomerular afferent and efferent arterioles.An exhaustive morphometric study revealed that, during postnatal development of the rat kidney, the glomerular volume increased mainly through the elongation of capillaries, and the elongation was accompanied by expansion of glomerular basement membranes (GBM). Electron microscopy showed that "GBM-outpockets", where GBM are thought to be expanded, were distributed chiefly in the periphery of the glomeruli.The cytoskeletons in the renal glomerular podocyte was studied in experimental models. In the isolated perfused kidneys, the glomerular filtration barrier was shown to be extensible and the cytoskeletons in the podocyte was thought to counteract against the excessive extension. In the Masugi-nephritis rats, retraction of the foot processes of the podocytes was accompanied by the reorganization of AFs, and these AFs seem to prevent of the detachment of podocytes from GBM.

比较了主动脉（弹性动脉）和肾内动脉（肌性动脉）内皮细胞中肌动蛋白丝（AF）的分布。在成年大鼠，这些动脉段的内皮AF的分布模式几乎是相同的。相反，主动脉内皮细胞中的AF显示出从出生时的应力纤维到成人的外周带的重组。肾内动脉内皮下基底膜沿动脉树走行呈现沿着不均一性，为了比较弹性动脉和肌性动脉的中膜超微结构，我们研究了肺内动脉，在肺内可追踪到两种动脉的过渡。结果表明，过渡突然发生在肺内，没有任何中间段。肌球蛋白重链异构体的免疫细胞化学研究揭示了肾小球传入和传出小动脉之间的分子异质性，详尽的形态计量学研究表明，在大鼠肾脏出生后的发育过程中，肾小球体积的增加主要是通过毛细血管的伸长，并伴随着肾小球基底膜（GBM）的扩张。电镜下可见肾小球基底膜扩张的“GBM-外袋”主要分布于肾小球周围。在离体灌注的肾脏中，肾小球滤过屏障被证明是可扩展的，足细胞中的细胞骨架被认为可以抵消过度的扩展。在Masugi肾炎大鼠中，足细胞足突的收缩伴随着AF的重组，这些AF似乎阻止足细胞从GBM脱离。