Biffo S, Grillo M, Margolis F L
Department of Neurosciences, Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110.
Neuroscience. 1990;35(3):637-51. doi: 10.1016/0306-4522(90)90335-2.
Aminoacylhistidine dipeptides are present in the nervous tissue of many species. The olfactory mucosa and bulb of many vertebrates are rich in carnosine (beta-alanyl-L-histidine). Two related dipeptides homocarnosine (gamma-aminobutyryl-L-histidine) and anserine (beta-alanyl-N-methyl-L-histidine) are present in the CNS of mammals and birds, respectively. This manuscript describes the production, characterization and use in immunolocalization studies of antisera directed against carnosine and anserine. The anserine antiserum is highly specific for anserine while the carnosine antiserum cross-reacts with all three dipeptides. The differential specificity of the antisera, coupled with chemical characterization of the dipeptide composition of various brain regions, has permitted assignment of the cellular localization of the various dipeptides. Immunocytochemical localization of anserine has not been previously reported. Carnosine immunoreactivity in the olfactory system is restricted to the mature neurons in the olfactory mucosa, their axons and synaptic terminations in the glomerular layer of the olfactory bulb. Similar reactivity is seen in the accessory olfactory system. Astrocytes and cerebellar Bergmann glia seem to account for all the non-olfactory carnosine-like immunoreactive staining in the rodent brain. In contrast, in the avian CNS where anserine is chemically abundant, anserine-like immunoreactivity is widespread and apparently exclusively associated with glial cells. Thus, the olfactory receptor neurons appear to be the only neuronal population that expresses carnosine. Elsewhere in the CNS the aminoacylhistidine dipeptides are associated with various populations of glia.
氨酰组氨酸二肽存在于许多物种的神经组织中。许多脊椎动物的嗅黏膜和嗅球富含肌肽（β-丙氨酰-L-组氨酸）。两种相关的二肽，即同型肌肽（γ-氨基丁酰-L-组氨酸）和鹅肌肽（β-丙氨酰-N-甲基-L-组氨酸），分别存在于哺乳动物和鸟类的中枢神经系统中。本手稿描述了针对肌肽和鹅肌肽的抗血清的制备、特性及其在免疫定位研究中的应用。鹅肌肽抗血清对鹅肌肽具有高度特异性，而肌肽抗血清与所有三种二肽都有交叉反应。抗血清的差异特异性，加上对不同脑区二肽组成的化学表征，使得能够确定各种二肽的细胞定位。此前尚未报道过鹅肌肽的免疫细胞化学定位。嗅觉系统中的肌肽免疫反应性仅限于嗅黏膜中的成熟神经元、它们的轴突以及嗅球肾小球层中的突触终末。在副嗅觉系统中也观察到类似的反应性。星形胶质细胞和小脑伯格曼胶质细胞似乎是啮齿动物脑中所有非嗅觉类肌肽免疫反应性染色的原因。相比之下，在化学上富含鹅肌肽的鸟类中枢神经系统中，鹅肌肽样免疫反应性广泛存在，且显然仅与神经胶质细胞相关。因此，嗅觉受体神经元似乎是唯一表达肌肽的神经元群体。在中枢神经系统的其他部位，氨酰组氨酸二肽与各种神经胶质细胞群体相关。
