Lynch D R, Strittmatter S M, Venable J C, Snyder S H
J Neurosci. 1986 Jun;6(6):1662-75. doi: 10.1523/JNEUROSCI.06-06-01662.1986.
3H-Guanidinoethylmercaptosuccinic acid (GEMSA) selectively labels the carboxypeptidase B-like enzyme enkephalin convertase (EC) in rat brain tissue sections. We have used autoradiography with 3H-GEMSA to map membrane-bound EC in the rat forebrain and, in conjunction with lesioning techniques, to localize EC to specific neuronal pathways. The highest levels of EC are in the median eminence. High levels of EC also occur in the hypothalamic magnocellular nuclei, in several nuclei of the amygdala, the lateral septum, and the bed nuclei of the stria terminalis. Knife-cut lesions of the stria terminalis increase EC posterior to the lesion in the stria and deplete EC from the stria adjacent to the bed nucleus, suggesting that EC, like enkephalins, is axonally transported within the stria terminalis. Ibotenic acid lesions of the caudate nucleus destroy binding in the substantia nigra pars reticulata ipsilateral to the lesion, suggesting that nigral EC is associated with axons originating in the caudate nucleus. We have also mapped EC in detail in the hippocampus. EC levels are highest near pyramidal cells of CA 3-4 and the dentate gyrus granule cells. Quinolinic acid lesions destroy both the granule and pyramidal cells and destroy all of the 3H-GEMSA labeling except for a small amount in the molecular layer of the dentate gyrus. Selective destruction of CA 3-4 pyramidal cells with kainic acid eliminates EC in the pyramidal cell region. Destruction of granule cells of the dentate gyrus with colchicine depletes binding in the dentate gyrus without any change in the area surrounding field CA 3-4. High levels of 3H-GEMSA binding are present in the hippocampus at least 3 d before birth. These observations suggest that in the hippocampus the majority of EC is associated with pyramidal cells, which have not been shown to contain enkephalins. 3H-GEMSA autoradiography of the trigeminal ganglion localizes EC to the sensory neurons and not to white matter tracts there. These studies demonstrate that while EC is contained in enkephalinergic pathways, it is also present in some neurons that do not contain enkephalins.
3H-胍基乙基巯基琥珀酸（GEMSA）可选择性地标记大鼠脑组织切片中的羧肽酶B样酶脑啡肽转化酶（EC）。我们使用3H-GEMSA放射自显影技术来绘制大鼠前脑中膜结合型EC的分布图，并结合损伤技术，将EC定位到特定的神经通路。EC水平最高的部位是正中隆起。在下丘脑大细胞神经核、杏仁核的几个神经核、外侧隔以及终纹床核中也有高水平的EC。终纹的刀切损伤会使损伤部位后方的终纹中EC增加，而终纹床核附近的终纹中EC减少，这表明EC与脑啡肽一样，在终纹中通过轴突运输。尾状核的鹅膏蕈氨酸损伤会破坏损伤同侧黑质网状部的结合，这表明黑质EC与起源于尾状核的轴突有关。我们还详细绘制了海马体中EC的分布图。EC水平在CA 3-4的锥体细胞和齿状回颗粒细胞附近最高。喹啉酸损伤会破坏颗粒细胞和锥体细胞，并消除所有的3H-GEMSA标记，除了齿状回分子层中的少量标记。用 kainic 酸选择性破坏CA 3-4锥体细胞会消除锥体细胞区域的EC。用秋水仙碱破坏齿状回颗粒细胞会使齿状回中的结合减少，而CA 3-4周围区域没有任何变化。在出生前至少3天，海马体中就存在高水平的3H-GEMSA结合。这些观察结果表明，在海马体中，大多数EC与锥体细胞有关，而锥体细胞尚未被证明含有脑啡肽。三叉神经节的3H-GEMSA放射自显影将EC定位到感觉神经元，而不是那里的白质束。这些研究表明，虽然EC存在于脑啡肽能通路中，但它也存在于一些不含脑啡肽的神经元中。
