Barnes K, Matsas R, Hooper N M, Turner A J, Kenny A J
MRC Membrane Peptidase Research Group, Department of Biochemistry, University of Leeds, U.K.
Neuroscience. 1988 Dec;27(3):799-817. doi: 10.1016/0306-4522(88)90184-4.
Endopeptidase-24.11 (sometimes referred to as 'enkephalinase') is a key cell-surface enzyme in the metabolism of neuropeptides. A previous immunohistochemical study mapped the enzyme in pig brain and indicated a striosomal ordering of the enzyme within the striatum. This point has now been confirmed by staining adjacent sections for acetylcholinesterase (by histochemistry) and endopeptidase-24.11 (by an immunoperoxidase method). While there were some general similarities in the mapping of these two hydrolases, e.g. in the caudate-putamen, globus pallidus, olfactory tubercle, substantia nigra and striatonigral tract, there were differences in intensity and in the microscopic distribution, e.g. as in striosomes for which acetylcholinesterase was diminished. Two other membrane peptidases, peptidyl dipeptidase A ('angiotensin converting enzyme') and aminopeptidase N, were also mapped by the same immunohistochemical method. Peptidyl dipeptidase A had some similarities with endopeptidase-24.11, e.g. in its concentration within the striatal nuclei, but clear differences were also apparent, in particular the absence of staining of the former in the globus pallidus and olfactory tubercle. Immunostaining for aminopeptidase N, in contrast to the other peptidases, was observed as a diffuse staining throughout the gray matter. At the microscopic level, two important differences were that staining for aminopeptidase N and peptidyl dipeptidase A was very intense throughout the vasculature of the brain and that striatal efferent bundles of unmyelinated fibres staining positively for endopeptidase-24.11 were depleted of the other two peptidases. All three peptidases were identified in the pia mater. Thus, endopeptidase-24.11, unlike peptidyl dipeptidase A and aminopeptidase N, is a marker for a set of striatal efferent fibres in pig brain.
内肽酶-24.11（有时被称为“脑啡肽酶”）是神经肽代谢中的一种关键细胞表面酶。先前的一项免疫组织化学研究绘制了该酶在猪脑中的分布图，并表明该酶在纹状体内呈纹体排列。现在，通过对相邻切片进行乙酰胆碱酯酶染色（通过组织化学方法）和内肽酶-24.11染色（通过免疫过氧化物酶法），这一点得到了证实。虽然这两种水解酶的分布图有一些总体相似之处，例如在尾状核-壳核、苍白球、嗅结节、黑质和纹状体黑质束中，但在强度和微观分布上存在差异，例如在乙酰胆碱酯酶减少的纹体中。另外两种膜肽酶，肽基二肽酶A（“血管紧张素转换酶”）和氨肽酶N，也通过相同的免疫组织化学方法进行了绘图。肽基二肽酶A与内肽酶-24.11有一些相似之处，例如在纹状体核内的浓度，但也有明显差异，特别是前者在苍白球和嗅结节中无染色。与其他肽酶相比，氨肽酶N的免疫染色在整个灰质中呈弥漫性染色。在微观层面，两个重要差异是氨肽酶N和肽基二肽酶A在整个脑血管系统中的染色非常强烈，以及内肽酶-24.11染色阳性的纹状体传出无髓纤维束中没有另外两种肽酶。在软脑膜中鉴定出了所有三种肽酶。因此，与肽基二肽酶A和氨肽酶N不同，内肽酶-24.11是猪脑中一组纹状体传出纤维的标志物。
