Redecker P, Grube D, Jahn R
Abteilung Anatomie 1 der Medizinischen Hochschule, Hannover, Federal Republic of Germany.
Anat Embryol (Berl). 1990;181(5):433-40. doi: 10.1007/BF02433790.
Synaptophysin (protein p38), a major integral membrane glycoprotein of small presynaptic vesicles, was localized immunohistochemically in semithin sections of the superficial pineal gland of the Mongolian gerbil (Meriones unguiculatus). Synaptophysin immunoreactivity could be detected in all pinealocytes, which were visualized with antibodies directed against neuron-specific enolase (NSE) in adjacent sections. No p38 immunoreactivity was discernible in the interstitial glial cells, which showed a heterogeneous pattern of immunostaining for the intermediate filament proteins glial fibrillary acidic protein (GFAP) and vimentin. Pinealocytes exhibited considerable intercellular differences in the densities of immunostaining. The various degrees of synaptophysin immunoreactivities in pinealocytes were not correlated with the densities of NSE immunostaining. Nerve terminals and varicosities displayed stronger immunoreactivities than pinealocytes. They were particularly numerous in the perivascular spaces. It is not clear whether this distribution indicates an innervation of pineal capillaries in addition to the functionally important innervation of pinealocytes. Several highly p38-positive dots of variable size were a conspicuous feature throughout the gland. By the consecutive semithin-thin section technique, they could be identified as processes of pinealocytes, filled with accumulations of small clear vesicles. Obviously, these vesicles represent the major site of synaptophysin immunoreactivity in pinealocytes. In the gerbil, similar vesicles have been ascribed a role in the secretory activity of the gland, and/or in the transport of calcium. The intercellular differences in the degrees of p38 immunostaining may, therefore, reflect different states of a specific cellular activity. The presence of synaptophysin in pinealocytes of the normal pineal, including the deep portions of the gland, emphasizes the paraneuronal character of these cells.
突触素（蛋白质p38）是突触前小泡的一种主要整合膜糖蛋白，通过免疫组织化学方法定位在长爪沙鼠（Meriones unguiculatus）松果体浅层的半薄切片中。在所有松果体细胞中均可检测到突触素免疫反应性，在相邻切片中用针对神经元特异性烯醇化酶（NSE）的抗体可观察到这些细胞。在间质神经胶质细胞中未发现p38免疫反应性，这些细胞对中间丝蛋白胶质纤维酸性蛋白（GFAP）和波形蛋白呈现出异质性免疫染色模式。松果体细胞在免疫染色密度上表现出明显的细胞间差异。松果体细胞中不同程度的突触素免疫反应性与NSE免疫染色密度无关。神经末梢和膨体显示出比松果体细胞更强的免疫反应性。它们在血管周围间隙中特别多。尚不清楚这种分布是否表明除了对松果体细胞具有功能重要性的神经支配外，松果体毛细血管也有神经支配。整个腺体中有几个大小不一的高度p38阳性小点是一个显著特征。通过连续半薄-超薄切片技术，可将它们鉴定为充满小清亮小泡聚集的松果体细胞突起。显然，这些小泡代表了松果体细胞中突触素免疫反应性的主要部位。在沙鼠中，类似的小泡被认为在腺体的分泌活动和/或钙的运输中起作用。因此，p38免疫染色程度的细胞间差异可能反映了特定细胞活动的不同状态。正常松果体包括腺体深部的松果体细胞中存在突触素，强调了这些细胞的副神经元特征。
