Blaustein J D, Olster D H
Neuroscience and Behavior Program, University of Massachusetts, Amherst 01003.
J Neuroendocrinol. 1993 Feb;5(1):63-70. doi: 10.1111/j.1365-2826.1993.tb00364.x.
Using immunocytochemical techniques, cells containing estrogen and progestin receptors have been observed in many discrete regions of the guinea-pig forebrain, including the mediobasal hypothalamus and preoptic area. While most reaction product is located within cell nuclei, we have reported abundant reaction product in perikaryal cytoplasm and neuronal processes as well. Ultrastructural analysis has revealed the presence of estrogen and progestin receptors in atypical subcellular sites within the hypothalamus, including dendrites and axon terminals. In order to determine if microtubule-dependent intracellular transport is involved in intraneuronal transport of steroid hormone receptors, ovariectomized guinea-pigs were injected intracerebroventricularly with the microtubule inhibitor, colchicine, and brain sections at the level of the hypothalamus were immunostained for estrogen receptors. This treatment resulted in the appearance of estrogen receptor immunoreactivity in the paraventricular and mediodorsal thalamic region, areas typically devoid of estrogen receptor-immunoreactive cells in guinea-pigs. In a second study on progestin receptors, we observed the colchicine-induced accumulation of progestin receptor immunoreactivity in the paraventricular thalamic, mediodorsal thalamic and lateral dorsal thalamic areas as well as in the medial amygdala, all areas typically devoid of progestin receptor immunoreactivity. While estradiol injection induced progestin receptor immunoreactivity in the hypothalamus and preoptic area as described previously, it had no effect on the colchicine-induced accumulation in the thalamus and amygdala. These results provide evidence that in some neurons, progestin receptors and estrogen receptors are transported intracellularly, apparently at a rapid enough rate that they do not ordinarily accumulate within the perikaryon.
运用免疫细胞化学技术，已在豚鼠前脑的许多离散区域观察到含有雌激素和孕激素受体的细胞，包括中基底下丘脑和视前区。虽然大多数反应产物位于细胞核内，但我们也曾报道在胞体细胞质和神经突中也有大量反应产物。超微结构分析显示，在下丘脑的非典型亚细胞部位，包括树突和轴突终末，存在雌激素和孕激素受体。为了确定微管依赖性细胞内运输是否参与类固醇激素受体的神经元内运输，给去卵巢的豚鼠脑室内注射微管抑制剂秋水仙碱，并对下丘脑水平的脑切片进行雌激素受体免疫染色。这种处理导致在室旁核和丘脑背内侧区域出现雌激素受体免疫反应性，而在豚鼠中这些区域通常没有雌激素受体免疫反应性细胞。在第二项关于孕激素受体的研究中，我们观察到秋水仙碱诱导的孕激素受体免疫反应性在丘脑室旁核、丘脑背内侧核和丘脑背外侧核区域以及杏仁核内侧积累，所有这些区域通常都没有孕激素受体免疫反应性。虽然如前所述，雌二醇注射可诱导下丘脑和视前区的孕激素受体免疫反应性，但它对秋水仙碱诱导的丘脑和杏仁核积累没有影响。这些结果提供了证据，表明在一些神经元中，孕激素受体和雌激素受体在细胞内运输时，显然速度足够快，以至于它们通常不会在胞体内积累。
