Summary: Quantitative morphometric analysis of the terminal blood network has been performed in human spinal cord segments chosen (C3, C8, Th5, L1, L3, two of them from spinal intumescences - C8 and L1). At the same time, analysis of fibrilar glia was provided along with analysis of oligodendroglia. The number of capillaries per unit area was determined in various regions of the gray and white matter of all segments studied. The density of capillaries was expressed as a percentage of the whole given area. I gray matter, the number of capillaries and, to a greater extent, the areas of capillaries, increase from posterior columns to anterior ones, where their area is largest. In white matter, the network of capillaries is richest and occupies the largest area in the anterior fasciculus while it is decreased to the fasciculus posterior. Values of the number and areas of capillaries in gray and especially in white matter increase from cervical segments to lumbar ones, where the values are highest. By evaluation of fibrilar glia after starting with the immunoperoxidase reaction ofn the acidic fibrilar protein, it was found that these structures are present more in the gray matter of anterior columns than in lateral and posterior ones, while in the white matter there are not such markant differences. We could find slightly more cells in the anterior and lateral columns than in the posterior one. By comparison of the glia in various segments, we found no significant difference, and it can be stated that the pattern of fibrilar glia does not change in the segments studied. On the other hand, gradually increasing numbers of oligodendrocytes were found as we moved from cervical to lumbar segments. Their distribution pattern in the white matter of various segments were nearly identical. Evaluation of the dependence of oligodendrocytes on the number of capillaries showed that the number of oligodendrocytes per capillary increases from anterior to posterior fascicles, while there are not significant differences between various segments. If the number of oligodendrocytes is realted to the normalized capillary area the order of increasing values from the anterior to posterior fascicules and from the lumbar to cervival segment can be established.
All findings are discussed in view of results from human radiation myelopathies. Both the terminal blood capillary network pattern and the glial cell pattern are parts of the substrate which is responsible for radiation injury repair. Due to misrepair, some forms of radiation myelopathy can be observed clinically. In this paper certain findings are mentioned concerning cytokines which take part in or are responsible for some cell reactions and which have been found in radiation injury reactions. Cytokines can cause apoptosis as well. This field of radiobiology has not been explored in great detail and one can state that we are standing in front of a large and very interesting chapter of research.
Quantitative analysis of the terminal capillary network and glia in human spinal cord -possible update to elucidation of the radiation myelopathy
