标题:Ultrastructural identification of substance P cells and their processes in rat sensory ganglia and their terminals in the spinal cord by immunocytochemistry
期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1977
卷号:74
期号:9
页码:4050-4054
DOI:10.1073/pnas.74.9.4050
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The unlabeled substance P (SP) antibody-peroxidase-antiperoxidase reaction was used on tissue prior to embedding in epoxy reins for ultrastructural identification of the SP cell and its immunoreactive granules. The SP cell is 10-20 {micro}m in diameter and has sparse cytoplasm with numerous intensely reactive SP granules 100-300 nm across, large clear vacuoles, elaborate smooth endoplasmic reticulum, fragmentary rough endoplasmic reticulum, dispersed ribosomes, few mitochondria, and a modest Glogi apparatus. The large SP-reactive granules are discharged into the extracellular space, either with cell membrane intact or as unbound dense material. The membrane-bound dense granucles are transported intact through endothelial cells into the blood or are picked up by Schwann cells and fibroblasts. Other SP-reactive granules lose their limiting membranes, fragment, and then disperse into fine immunoreactive grains that bind to the extracellular matrix and to collagen. Dispersed SP-reactive granules are transported within myriad pinocytotic vesicles across endothelial cells with numerous luminal plications and are discharged into the blood. Pinocytosis of dispersed SP-reactive material, that can be detected intracellularly, also occurs in Schwann cells and fibroblasts. The SP axons to the substantia gleatinosa are unmyelinated or finely myelinated. Their synaptic varicosities display a generalized axoplasmic immunoreactivity, which also occurs in and around small vesicles. The larger SP synaptic vesicles are intensely reactive.