Kummer W, Acker H
Institute for Anatomy and Cell Biology, Justus-Liebig University, Giessen, Germany.
Histochem Cell Biol. 1997 Feb;107(2):151-8. doi: 10.1007/s004180050099.
Small intensely fluorescent (SIF) cells are paraganglionic cells derived from sympathicoblasts which may serve as interneurons, endo-/paracrine cells or arterial chemoreceptors within sympathetic ganglia. Like paraganglionic cells of other locations, e.g., carotid body glomus cells, they are responsive to hypoxia. Recent studies on glomus cells and other hypoxia-sensing cells suggested the involvement of a b558-type cytochrome and intracellular generation of H2O2 in the process of oxygen sensing. In the present study, we demonstrate the occurrence of the small subunit of cytochrome b558, p22phox, in SIF cells of guinea-pig sympathetic ganglia by immunohistochemistry using two different antisera. H2O2 production was monitored in explanted intact superior cervical ganglia of 2-day-old rats by confocal laser scanning analysis of rhodamine 123 fluorescence generated due to oxidation of dihydrorhodamine 123 by H2O2. Using this technique, SIF cell clusters appeared as sites of highest H2O2 production within the ganglia. Thus, SIF cells exhibit two key features of an oxidase system generating reactive oxygen species. This may be involved in the proposed chain of events in oxygen sensing, but alternative cellular functions of this system have also to be considered.
小而强荧光（SIF）细胞是源自交感母细胞的副神经节细胞，在交感神经节内可作为中间神经元、内分泌/旁分泌细胞或动脉化学感受器。与其他部位的副神经节细胞（如颈动脉体球细胞）一样，它们对缺氧有反应。最近对球细胞和其他缺氧感受细胞的研究表明，b558型细胞色素和细胞内H2O2的产生参与了氧感受过程。在本研究中，我们使用两种不同的抗血清，通过免疫组织化学方法证明了细胞色素b558小亚基p22phox在豚鼠交感神经节SIF细胞中的存在。通过共聚焦激光扫描分析二氢罗丹明123被H2O2氧化产生的罗丹明123荧光，监测2日龄大鼠离体完整颈上神经节中的H2O2产生情况。利用该技术，SIF细胞簇在神经节内表现为H2O2产生量最高的部位。因此，SIF细胞展现出产生活性氧的氧化酶系统的两个关键特征。这可能参与了氧感受中提出的一系列事件，但也必须考虑该系统的其他细胞功能。
