MEMBRANE PEPTIDASES IN THE PERIPHERAL NERVOUS-SYSTEM OF THE PIG - THEIR LOCALIZATION BY IMMUNOHISTOCHEMISTRY AT LIGHT AND ELECTRON-MICROSCOPIC LEVELS
MEMBRANE PEPTIDASES IN THE PERIPHERAL NERVOUS-SYSTEM OF THE PIG - THEIR LOCALIZATION BY IMMUNOHISTOCHEMISTRY AT LIGHT AND ELECTRON-MICROSCOPIC LEVELS
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DOI：
10.1016/0306-4522(91)90265-p
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发表时间：
1991-01-01
期刊：
影响因子：
3.3
通讯作者：
KENNY, AJ
中科院分区：
文献类型：
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作者：
BARNES, K;BOURNE, A;KENNY, AJ
五种膜肽酶的存在和细胞定位已经在猪的周围神经，包括自主神经系统中进行了研究。内肽酶-24.11（“脑啡肽酶”）肽基二肽酶A，氨肽酶N，氨肽酶W和二肽基肽酶IV进行了研究，从神经样品制备的膜的酶测定和免疫过氧化物酶组织化学在光和两种情况下，内肽酶-24.11和氨肽酶W，在电子显微镜水平。内肽酶-24.11在所有类型的神经中与雪旺细胞膜相关，包括主要含有有髓纤维的主要神经以及自主神经，如迷走神经、脾神经和交感神经链，在与有髓和无髓纤维相关的膜中观察到染色。内肽酶-24.11的雪旺细胞定位通过与胶质细胞酸性蛋白的免疫染色和电子显微镜的相关性来证实。已知该肽酶在神经肽中具有广泛的敏感底物库，其在此显示包括血管活性肠多肽（K（m）268-mu-M，k（cat）568 min-1），其是存在于外周神经纤维中的许多神经肽之一。三种肽酶，肽基二肽酶A，氨肽酶N和二肽基肽酶IV，与周围神经的微血管。在结缔组织成分中也观察到氨肽酶N，包括神经束膜。氨肽酶W是唯一的五种肽酶中具有神经元定位。这在无髓鞘和有髓鞘神经中观察到，并通过与神经丝蛋白染色模式和电子显微镜免疫过氧化物酶染色的比较得到支持。这一观察结果是出乎意料的，因为氨肽酶W尚未被检测为脑中的神经元标记物。膜肽酶在周围神经中的一些可能的作用进行了讨论。
The presence and cellular localization of five membrane peptidases has been investigated in peripheral nerves, including those of the autonomic nervous system, in the pig. Endopeptidase-24.11 ("enkephalinase") peptidyl dipeptidase A, aminopeptidase N, aminopeptidase W and dipeptidyl peptidase IV were studied by both enzymic assays of membranes prepared from samples of nerve and by immunoperoxidase histochemistry at light and in two cases, endopeptidase-24.11 and aminopeptidase W, at electron microscopic levels. All five peptidases could be quantified by enzymic assay, though the activities were about 1% of those in renal microvilli and less than those of choroid plexus membranes.Endopeptidase-24.11 was associated with Schwann cell membranes in all types of nerve examined, including major nerves containing predominantly myelinated fibres as well as autonomic nerves, such as the vagus and splenic nerves and the sympathetic chain, staining being observed in membranes associated with myelinated and unmyelinated fibres. The Schwann cell location of endopeptidase-24.11 was confirmed by correlation with immunostaining for glial fibrillary acidic protein and by electron microscopy. This peptidase is known to have a wide repertoire of susceptible substrates among neuropeptides which was here shown to include vasoactive intestinal polypeptide (K(m) 268-mu-M, k(cat) 568 min-1), one of a number of neuropeptides present in peripheral nerve fibres. Three of the peptidases, peptidyl dipeptidase A, aminopeptidase N and dipeptidyl peptidase IV, were associated with microvessels of peripheral nerves. Aminopeptidase N was also observed in connective tissue elements, including the perineurium. Aminopeptidase W was unique among the five peptidases in having a neuronal localization. This was observed in unmyelinated and myelinated nerves and was supported by comparison with the pattern of staining observed for neurofilament protein and by electron microscopic immunoperoxidase staining. This observation was unexpected since aminopeptidase W has not been detected as a neuronal marker in the brain. Some possible roles for the membrane peptidases in peripheral nerves are discussed.