Galeazza M T, Garry M G, Yost H J, Strait K A, Hargreaves K M, Seybold V S
Department of Cell Biology and Neuroanatomy, University of Minnesota, School of Medicine, Minneapolis 55455, USA.
Neuroscience. 1995 May;66(2):443-58. doi: 10.1016/0306-4522(94)00545-g.
Several indices of peptidergic, primary afferent neural transmission in rat at the level of the lumbar spinal cord exhibited differential changes over time in response to adjuvant-induced inflammation of the hindpaw. The indices were measurements of the production of messenger RNA encoding the precursors for substance P and calcitonin gene-related peptide in dorsal root ganglia, the storage of substance P and calcitonin gene-related peptide in the dorsal spinal cord and the release of the peptides evoked by application of capsaicin to the dorsal spinal cord. A 47% decrease in the content of immunoreactive substance P in the dorsal half of the lumbar spinal cord, as determined by radioimmunoassay, was measured at 6 h following the injection of complete Freund's adjuvant into the hindpaw. Decreased content of immunoreactive SP persisted for four days, but was no longer present at eight days after the adjuvant injection. The content of immunoreactive calcitonin gene-related peptide in the dorsal spinal cord was decreased by 29% at one day following the injection of adjuvant into the rat hindpaw and 43% at two days; the content then increased to a level greater than that of control animals at eight days. The amount of messenger RNA encoding preprotachykinin and prepro-calcitonin gene-related peptide in L4-L6 dorsal root ganglia was determined from northern blot analysis of the total messenger RNA extracted from the dorsal root ganglia. Each species of messenger RNA had increased compared to the control animals at two days following the injection of adjuvant into the rat hindpaws and remained elevated after eight days. Thus, an increase in the messenger RNAs encoding substance P and calcitonin gene-related peptide in the dorsal root ganglia preceeded the recovery of the content of the peptides in the spinal cord. Morphometric studies of calcitonin gene-related peptide-immunoreactive perikarya in the L4 dorsal root ganglia indicated that the increase in messenger RNA occurred in neurons of the size that normally express calcitonin gene-related protein. Radioimmunoassay of the superfusate of the dorsal half of the lumbar spinal cord was used to measure the release of immunoreactive substance P and immunoreactive calcitonin gene-related protein in vitro. Although the basal release of immunoreactive substance P and immunoreactive calcitonin-gene related protein from the dorsal spinal cord was constant throughout the time points examined, changes occurred in the release of peptide evoked by 10 microM capsaicin. The capsaicin-evoked release of immunoreactive substance P was decreased at 6 h and eight days post-injection of adjuvant.(ABSTRACT TRUNCATED AT 400 WORDS)
在大鼠腰脊髓水平，几种肽能初级传入神经传递指标，在佐剂诱导后爪炎症反应过程中随时间呈现出不同变化。这些指标包括对背根神经节中编码P物质和降钙素基因相关肽前体的信使核糖核酸生成量的测定、背脊髓中P物质和降钙素基因相关肽的储存量测定，以及将辣椒素应用于背脊髓后所诱发的肽释放量测定。通过放射免疫测定法测得，在将完全弗氏佐剂注射到后爪6小时后，腰脊髓背侧半中免疫反应性P物质含量下降了47%。免疫反应性SP含量的下降持续了4天，但在佐剂注射8天后不再存在。在将佐剂注射到大鼠后爪1天后，背脊髓中免疫反应性降钙素基因相关肽含量下降了29%，2天时下降了43%；然后在8天时该含量增加到高于对照动物的水平。通过对从背根神经节提取的总信使核糖核酸进行Northern印迹分析，测定了L4 - L6背根神经节中编码前速激肽原和前降钙素基因相关肽的信使核糖核酸量。在将佐剂注射到大鼠后爪2天后，与对照动物相比，每种信使核糖核酸的量都增加了，并且在8天后仍保持升高。因此，背根神经节中编码P物质和降钙素基因相关肽的信使核糖核酸增加先于脊髓中肽含量的恢复。对L4背根神经节中降钙素基因相关肽免疫反应性核周体的形态计量学研究表明，信使核糖核酸的增加发生在通常表达降钙素基因相关蛋白的大小的神经元中。使用腰脊髓背侧半的灌流液进行放射免疫测定，以测量体外免疫反应性P物质和免疫反应性降钙素基因相关蛋白的释放。尽管在所检查的各个时间点，背脊髓中免疫反应性P物质和免疫反应性降钙素基因相关蛋白的基础释放量是恒定的，但10微摩尔辣椒素诱发的肽释放量发生了变化。在注射佐剂后6小时和8天时，辣椒素诱发的免疫反应性P物质释放量下降。（摘要截选至400字）
