Perlmutter L S, Barrón E, Myers M, Saperia D, Chui H C
Department of Neurology, University of Southern California School of Medicine, Los Angeles 90033.
J Comp Neurol. 1995 Jan 30;352(1):92-105. doi: 10.1002/cne.903520107.
Amyloid P component is a normal serum protein that is highly conserved across phylogeny. Although it resembles the classic acute-phase reactant C-reactive protein, and is considered to be a normal extracellular matrix component, its physiologic role in humans is unknown. Amyloid P component is also colocalized with accumulations of all recognized forms of amyloid. The present study uses light and electron microscopy to compare the cerebral localization of amyloid P component in cases with (n = 19) and without (n = 15) Alzheimer's disease (AD). In non-AD cases, amyloid P component was predominantly localized to the cerebrovasculature. Perivascular staining was observed in most cases, more so in the white than in the gray matter. In AD cases, amyloid P component was localized to all three characteristics histopathologic lesions, namely, neurofibrillary tangles, senile plaques, and amyloid angiopathy. Furthermore, in cases with prominent staining of gray matter parenchymal lesions, intravascular staining was decreased. Given the fixation and processing methods used, amyloid P component was never seen to be localized to the cerebrovascular basement membrane. These data argue against amyloid P component's postulated role as the anchor for vascular beta-amyloid deposition. Because there is no evidence for intrinsic amyloid P component production in brain, its perivascular and parenchymal distributions suggest either compromise of the blood-brain barrier or transport across vascular endothelium.
淀粉样蛋白P成分是一种正常的血清蛋白，在系统发育过程中高度保守。尽管它类似于经典的急性期反应物C反应蛋白，并且被认为是一种正常的细胞外基质成分，但其在人类中的生理作用尚不清楚。淀粉样蛋白P成分也与所有公认形式的淀粉样蛋白沉积物共定位。本研究使用光学显微镜和电子显微镜比较了患有（n = 19）和未患有（n = 15）阿尔茨海默病（AD）的病例中淀粉样蛋白P成分的脑定位。在非AD病例中，淀粉样蛋白P成分主要定位于脑血管系统。在大多数病例中观察到血管周围染色，白质中的染色比灰质中的更多。在AD病例中，淀粉样蛋白P成分定位于所有三种特征性组织病理学病变，即神经原纤维缠结、老年斑和淀粉样血管病。此外，在灰质实质病变染色突出的病例中，血管内染色减少。鉴于所使用的固定和处理方法，从未观察到淀粉样蛋白P成分定位于脑血管基底膜。这些数据反驳了淀粉样蛋白P成分作为血管β淀粉样蛋白沉积锚定物的假设作用。由于没有证据表明大脑中存在内源性淀粉样蛋白P成分产生，其血管周围和实质分布表明血脑屏障受损或通过血管内皮运输。
