| Abstract: | The objective of the present study was to determine whether systemic hypothermia up-regulated vimentin and glial fibrillary acidic protein (GFAP) expression in the spinal cord as a result of trauma in normothermic rats. Experimental rats underwent thoracic laminectomy alone or laminectomy plus severe spinal cord compression, with or without reduction of core temperature. In hypothermic rats without trauma, vimentin was expressed in ependymal cells and a few intramedullary vessels but not in capillaries. Normothermic rats with trauma exhibited a marked up-regulation of vimentin in the capillaries and in reactive astrocytes in all thoracic segments of the spinal cord. Expression of vimentin was significantly reduced in hypothermic rats with trauma. Expression of GFAP was reduced in hypothermic rats without trauma. However, trauma induced up-regulation of GFAP in astrocytes in all thoracic segments. Hypothermia reduced this response in rats with trauma but to a lesser extent than vimentin. These results suggest that systemic hypothermia reduces the up-regulation of vimentin in capillaries and reactive astrocytes in injured normothermic rats and support the hypothesis that systemic hypothermia influences microvascular and astrocyte responses in the peri-injury zones following spinal cord compression trauma. |
