Jin S L, Han V K, Simmons J G, Towle A C, Lauder J M, Lund P K
Department of Physiology, University of North Carolina School of Medicine, Chapel Hill 27514.
J Comp Neurol. 1988 May 22;271(4):519-32. doi: 10.1002/cne.902710405.
Although glucagonlike immunoreactants (GLIs) are present in the central nervous system of several mammalian species, their structural relationship with pancreatic proglucagon is not defined, and their precise anatomical distribution has not been studied extensively. To obtain further information about the structure and biological significance of brain GLIs, the anatomical distribution of three different antigenic determinants of pancreatic proglucagon--glucagonlike peptide I (GLP-I), glucagon, and glicentin--was mapped in the brain of colchicine-treated rats by immunocytochemistry using the avidin-biotin-peroxidase method. Neuronal cell bodies immunoreactive with antisera specific for GLP-I, glucagon, and glicentin were found only in the caudal medulla oblongata. Within the caudal medulla immunostained cell bodies were found at levels from approximately 0.55 mm rostral to the obex to 0.45 mm caudal to the obex, and were located within the nucleus of the solitary tract (NTS) and the dorsal (MdD) and ventral (MdV) parts of the medullary reticular nucleus. The NTS contained three times more immunoreactive cell bodies than the MdD and MdV, and these cell bodies were located in the midline, medial, and lateral subnuclei of the caudal third of the NTS. Immunostaining of the same cell bodies in paired adjacent sections incubated with GLP-I and glucagon antisera or glucagon and glicentin antisera provided evidence for coexistence of the three antigens within the same neurons of the NTS. Nerve fibers and terminals immunoreactive with GLP-I, glucagon, and glicentin antisera were widely distributed throughout the rat brain and there was no discernible difference in the distribution of fibers and terminals immunoreactive with each of the three antisera. The highest densities of immunostained fibers and terminals were observed in the hypothalamus, thalamus, and septal regions, and the lowest in the cortex and hindbrain. The localization of neuronal cell bodies containing GLP-I, glucagon, and glicentin within the NTS and the MdD and MdV, and the extensive distribution of immunoreactive fibers and terminals throughout the rat brain suggest a role for these peptides in the integration of autonomic as well as central nervous system functions.
尽管胰高血糖素样免疫反应物（GLIs）存在于几种哺乳动物的中枢神经系统中，但其与胰高血糖素原的结构关系尚未明确，且其精确的解剖分布也未得到广泛研究。为了获取有关脑GLIs结构和生物学意义的更多信息，采用抗生物素蛋白-生物素-过氧化物酶法，通过免疫细胞化学技术，在秋水仙碱处理的大鼠脑中绘制了胰高血糖素原的三种不同抗原决定簇——胰高血糖素样肽I（GLP-I）、胰高血糖素和肠胰高血糖素的解剖分布图。仅在延髓尾部发现了对GLP-I、胰高血糖素和肠胰高血糖素特异性抗血清呈免疫反应的神经元细胞体。在延髓尾部，免疫染色的细胞体位于从闩部向前约0.55毫米至闩部向后0.45毫米的水平，且位于孤束核（NTS）以及延髓网状核的背侧（MdD）和腹侧（MdV）部分。NTS中免疫反应性细胞体的数量是MdD和MdV的三倍，这些细胞体位于NTS尾侧三分之一的中线、内侧和外侧亚核中。用GLP-I和胰高血糖素抗血清或胰高血糖素和肠胰高血糖素抗血清孵育的配对相邻切片中相同细胞体的免疫染色，为三种抗原在NTS的同一神经元中共存提供了证据。与GLP-I、胰高血糖素和肠胰高血糖素抗血清呈免疫反应的神经纤维和终末广泛分布于整个大鼠脑内，且三种抗血清免疫反应的纤维和终末分布没有明显差异。在丘脑、下丘脑和隔区观察到免疫染色纤维和终末的密度最高，而在皮质和后脑密度最低。NTS以及MdD和MdV中含有GLP-I、胰高血糖素和肠胰高血糖素的神经元细胞体的定位，以及免疫反应性纤维和终末在整个大鼠脑内的广泛分布，表明这些肽在自主神经系统以及中枢神经系统功能整合中发挥作用。
