Blaustein J D
Neuroscience and Behavior Program and Psychology Department, University of Massachusetts, Amherst 01003.
Endocrinology. 1992 Sep;131(3):1336-42. doi: 10.1210/endo.131.3.1380440.
The existence of cytoplasmic estrogen receptors (ERs) has been reported in the guinea pig brain using immunocytochemical techniques. While cytoplasmic ERs have been reported recently in other species, such as opossum, musk shrew, and ferrets, an exclusively cell nuclear pattern of ER immunoreactivity has been reported in the rat brain. Because all studies that have reported the existence of cytoplasmic ERs in the brain have used the H 222 monoclonal antibody, the possibility exists that this observation is idiosyncratic to this antibody. In the present experiment three antibodies directed against diverse epitopes on the ER protein were used to immunocytochemically stain ERs in rat brain. With each antibody, ER immunoreactivity was observed in the hypothalamus, preoptic area, amygdala, and midbrain periaqueductal gray. In all cases we observed the highest density of reaction product in cell nuclei, but extensive cytoplasmic immunostaining was observed in most areas as well. In addition to demonstrating the existence of neural ER immunoreactivity in perikaryal cytoplasm and cytoplasmic processes in the brain, this study suggests that the neural cytoplasmic ER immunoreactivity is not just a small fragment of the receptor protein; rather, it is likely to be the entire receptor.
利用免疫细胞化学技术，已报道在豚鼠大脑中存在细胞质雌激素受体（ERs）。虽然最近在其他物种（如负鼠、麝鼩和雪貂）中也报道了细胞质ERs，但在大鼠大脑中报道的ER免疫反应性呈现出仅位于细胞核的模式。由于所有报道大脑中存在细胞质ERs的研究都使用了H 222单克隆抗体，所以存在这种观察结果是该抗体所特有的可能性。在本实验中，使用了三种针对ER蛋白不同表位的抗体对大鼠大脑中的ERs进行免疫细胞化学染色。使用每种抗体时，在下丘脑、视前区、杏仁核和中脑导水管周围灰质中均观察到了ER免疫反应性。在所有情况下，我们在细胞核中观察到最高密度的反应产物，但在大多数区域也观察到了广泛的细胞质免疫染色。除了证明大脑中神经ER免疫反应性存在于胞体细胞质和细胞质突起中之外，本研究还表明神经细胞质ER免疫反应性并非仅仅是受体蛋白的一小部分；相反，它很可能是完整的受体。
