Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association Vol. 2; no. 6; pp. 434 - 441
• Main Authors: Aoki, Yasuo, Maruo, Souji, Arakawa, Akira, Sasaki, Sadao, Hori, Seiki
• Format: Journal Article
• Language: English
• Published: Tokyo Elsevier B.V 01.11.1997; Springer; Japanese Orthopaedic Association; Springer Nature B.V
• Subjects: Biological and medical sciences; Cerebrospinal fluid. Meninges. Spinal cord; confocal laser scanning microscopy; electron probe X-ray microanalysis; experimental epidural tumor; Medical sciences; Multiple sclerosis; Nervous system (semeiology, syndromes); Neurology; potential-sensitive molecular probe; spinal cord compression; electron probe X-ray microanalysis; experimental epidural tumor; spinal cord compression; potential-sensitive molecular probe; confocal laser scanning microscopy; Nervous system diseases; Compression; Spinal cord; Rat; Spine; Rodentia; Diseases of the osteoarticular system; Microanalysis; Histology; X ray; Spine disease; Malignant tumor; Experimental study; Vertebrata; High voltage electron microscopy; Electron probe; Mammalia; Animal; Spinal cord disease
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1007/BF02488932

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.