FMRFamidelike peptides of Homarus americanus: distribution, immunocytochemical mapping, and ultrastructural localization in terminal varicosities.
FMRFamidelike peptides of Homarus americanus: distribution, immunocytochemical mapping, and ultrastructural localization in terminal varicosities.
复制标题
美洲白鹤的 FMRF 酰胺样肽：末端静脉曲张的分布、免疫细胞化学图谱和超微结构定位。
DOI：
10.1002/cne.902660102
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Kravitz,EA
中科院分区：
文献类型：
--
作者：
Kobierski,LA;Beltz,BS;Trimmer,BA;Kravitz,EA
用免疫细胞化学和放射免疫技术研究了FMRFamid样肽在美洲龙虾神经系统中的分布。通过放射免疫测定，FMRF-酰胺样免疫反应性（FLI）在低水平（约100 mg/kg）中被发现。1 pmol/mg蛋白质），并且在神经分泌心包器官中的量高得多（60-100 pmol/mg蛋白质）。免疫细胞化学研究表明，FLI在大约300-350个细胞体，并在不同的神经元区域，神经元纤维束，和静脉曲张的结束。通过用FMRFamide、与FMRFamide具有相似羧基末端的肽（Met‐enkephalin‐Arg‐Phe、Phe‐Met‐Arg‐Tyr‐amide）、几种酰胺化肽（α-促黑素细胞激素、P物质、催产素）和proctolin（一种广泛分布于龙虾神经系统中的肽）预吸收抗血清，检测免疫染色的特异性。在这些物质中，只有FMRFamide阻断了染色。除了心包器官外，在与胸第二根相关的神经分泌区和腹神经索周围的结缔组织鞘中发现了显著水平的FLI。在所有三个区域，免疫细胞化学研究表明，FLI被定位到细纤维和相关的终端静脉曲张躺在靠近组织的表面，在其附近没有明显的目标。当在超微结构水平检查时，发现胸第二根和腹神经索鞘的免疫反应性静脉曲张距离组织表面几微米，并含有电子致密颗粒。在免疫反应阳性的神经索鞘末端，除了大而致密的颗粒外，还发现小而透明的囊泡，这些终末的出现和位置表明，龙虾中的FMRFamidelike肽具有神经激素作用。在血淋巴中发现低水平FLI的观察结果支持这一建议。此外，FLI定位于特定的神经元胞体、纤维束和神经元区域表明这些肽在以下方面可能具有功能作用：（1）视觉和嗅觉信息的整合，（2）前肠和后肠的功能，以及（3）外骨骼肌的控制。
The distribution of FMRFamidelike peptides was studied in the nervous system of the lobsterHomarus americanusby using immunocytochemical and radioimmunological techniques. By radioimmunoassay FMRF‐amidelike immunoreactivity (FLI) was found in low levels (ca. 1 pmol/mg protein) throughout the ventral nerve cord and in much higher amounts (60–100 pmol/mg protein) in the neurosecretory pericardial organs. Immunocytochemical studies showed FLI in approximately 300–350 cell bodies, and in distinct neuropil regions, neuronal fiber tracts, and varicose endings. Specificity of the immunostaining was tested by preabsorbing the antiserum with FMRFamide, with peptides having similar carboxyl termini to FMRFamide (Met‐enkephalin‐Arg‐Phe, Phe‐Met‐Arg‐Tyr‐amide), with several amidated peptides (α‐melanocyte‐stimulating hormone, substance P, oxytocin), and with proctolin, a peptide found widely distributed in the lobster nervous system. Of these substances, only FMRFamide blocked the staining.In addition to the pericardial organs, significant levels of FLI were found in neurosecretory regions associated with thoracic second roots and in the connective tissue sheath that surrounds the ventral nerve cord. In all three regions, immunocytochemical studies showed the FLI to be localized to fine fibers and associated terminal varicosities lying close to the surface of the tissue, with no obvious target in their immediate vicinity. When examined at the ultrastructural level, the immunoreactive varicosities of the thoracic second roots and of the ventral nerve cord sheaths were found a few microns from the surface of the tissue and contained electron‐dense granules. In the immunoreactive nerve cord sheath endings, in addition to the large, dense granules, small, clear vesicles were found. The appearance and location of these terminals suggest a neurohormonal role for FMRFamidelike peptides in lobsters. The observation that low levels of FLI are found in the hemolymph supports this suggestion. In addition, the localization of FLI to particular neuronal somata, fiber tracts, and neuropil regions suggests possible functional roles for these peptides in (1) integration of visual and olfactory information, (2) function of the anterior and posterior gut, and (3) the control of exoskeletal muscles.