Poston M R, Bailey M S, Schwarcz R, Shipley M T
Department of Anatomy and Cell Biology, University of Cincinnati College of Medicine, Ohio 45267.
J Comp Neurol. 1991 Sep 15;311(3):367-74. doi: 10.1002/cne.903110307.
The cellular localizations of the synthetic [3-hydroxyanthranilic acid oxygenase (3HAO)] and degradative [quinolinic acid phosphoribosyltransferase (QPRT)] enzymes of the endogenous excitotoxin quinolinic acid were studied in the adult rat main olfactory bulb by immunohistochemical techniques. 3HAO and QPRT were expressed only in astrocytes. The two enzymes were differentially expressed by astrocytes in a complementary pattern: 3HAO staining was strongest at the glomerular-external plexiform layer junction; QPRT staining was strongest at the glomerular-olfactory nerve layer junction. The complementary distributions of these metabolic enzymes suggests that there could be a gradient of quinolinic acid across the glomerular layer of the main olfactory bulb. Such a gradient could function to restrict the ingrowth of new olfactory axons to the glomeruli and/or to stabilize the formation of new synapses.
采用免疫组织化学技术，对内源性兴奋性毒素喹啉酸的合成酶[3-羟基邻氨基苯甲酸加氧酶（3HAO）]和降解酶[喹啉酸磷酸核糖基转移酶（QPRT）]在成年大鼠主嗅球中的细胞定位进行了研究。3HAO和QPRT仅在星形胶质细胞中表达。这两种酶在星形胶质细胞中以互补模式差异表达：3HAO染色在肾小球-外丛状层交界处最强；QPRT染色在肾小球-嗅神经层交界处最强。这些代谢酶的互补分布表明，在主嗅球的肾小球层可能存在喹啉酸梯度。这样的梯度可能起到限制新的嗅觉轴突长入肾小球和/或稳定新突触形成的作用。
