Monacci W T, Merrill M J, Oldfield E H
Surgical Neurology Branch, National Institute for Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Am J Physiol. 1993 Apr;264(4 Pt 1):C995-1002. doi: 10.1152/ajpcell.1993.264.4.C995.
Vascular permeability factor (VPF)/vascular endothelial growth factor (VEGF) is a approximately 43-kDa secreted protein that has been shown in bioassays to induce endothelial proliferation, angiogenesis, and capillary hyperpermeability. VPF has been suggested to play an important role in the physiology of normal vasculature. To further elucidate the natural functions of VPF in vivo, the expression of VPF in normal tissues was examined using Northern blot analysis and in situ hybridization histochemistry. VPF mRNA is expressed in the brain, kidney, liver, lung, and spleen of the healthy adult rat. On Northern blots, the relative abundance of VPF mRNA observed in these tissues was highest in the lung and lowest in the spleen. As determined by in situ hybridization, the patterns of VPF expression are organ specific. Hybridization of an antisense VPF probe was concentrated in the cerebellar granule cell layer of the brain and in the glomeruli and tubules of the kidney. In the liver and lung, intense hybridization was observed homogeneously throughout both tissues, demonstrating that VPF mRNA is present in virtually every hepatocyte and pulmonary alveolar cell. Hybridization to the spleen was weaker and more diffuse. The widespread expression and organ-specific distribution of VPF mRNA in normal rat tissues supports the suggestion of an extensive role for this factor in the physiology of normal vasculature.
血管通透性因子（VPF）/血管内皮生长因子（VEGF）是一种分子量约为43 kDa的分泌蛋白，生物测定显示其可诱导内皮细胞增殖、血管生成和毛细血管高通透性。有人提出VPF在正常脉管系统的生理过程中起重要作用。为了进一步阐明VPF在体内的自然功能，采用Northern印迹分析和原位杂交组织化学方法检测了VPF在正常组织中的表达。VPF mRNA在健康成年大鼠的脑、肾、肝、肺和脾中均有表达。在Northern印迹上，这些组织中观察到的VPF mRNA相对丰度在肺中最高，在脾中最低。通过原位杂交确定，VPF的表达模式具有器官特异性。反义VPF探针的杂交集中在脑的小脑颗粒细胞层以及肾的肾小球和肾小管中。在肝和肺中，在整个组织中均观察到强烈的杂交信号，表明几乎每个肝细胞和肺泡细胞中都存在VPF mRNA。与脾的杂交较弱且较弥散。VPF mRNA在正常大鼠组织中的广泛表达和器官特异性分布支持了该因子在正常脉管系统生理过程中发挥广泛作用的观点。
