Gorenstein C, Tran V T, Snyder S H
J Neurosci. 1981 Oct;1(10):1096-102. doi: 10.1523/JNEUROSCI.01-10-01096.1981.
To assess whether specific peptidases regulate neuropeptide disposition, we have examined histochemically the localization of dipeptidyl-aminopeptidase II (DAP II). With beta-naphthylamide (beta-NA) substrates, this enzyme has a selectivity for lysyl-alanyl-beta-NA. DAP II staining is highly localized to specific neuronal populations with no staining over glia. Areas in the brain with high densities of DAP II staining include the mitral cells in the olfactory bulb, polymorphic cells in the hippocampus, the paraventricular nucleus of the hypothalamus, and the anterior dorsal thalamus, Purkinje cells, and deep nuclei in the cerebellum. Staining occurs in virtually all cell groups in the inferior colliculus, red nucleus, oculomotor nucleus, and mesencephalic nucleus of the trigeminal nerve, the stratum album of the superior colliculus, as well as most cells in the cochlear and superior olivary nuclei. DAP II localizations do not correlate fully with those on any known neuropeptide. Of the numerous peptides evaluated, only glucagon competes substantially for the DAP Ii substrate, reducing enzymatic activity by 50% at a 2 x 10(-5) M concentration.
为评估特定肽酶是否调节神经肽的处置，我们通过组织化学方法检测了二肽基氨基肽酶II（DAP II）的定位。对于β-萘酰胺（β-NA）底物，该酶对赖氨酰丙氨酰-β-NA具有选择性。DAP II染色高度定位于特定的神经元群体，神经胶质细胞无染色。脑内DAP II染色高密度区域包括嗅球的二尖瓣细胞、海马的多形细胞、下丘脑室旁核、前背侧丘脑、浦肯野细胞以及小脑深部核团。在下丘、红核、动眼神经核、三叉神经中脑核、上丘白质层的几乎所有细胞群以及耳蜗核和上橄榄核的大多数细胞中均有染色。DAP II的定位与任何已知神经肽的定位并不完全相关。在评估的众多肽中，只有胰高血糖素能与DAP II底物大量竞争，在2×10⁻⁵ M浓度下可使酶活性降低50%。
