Regional Spinal Cord Blood Flow and Energy Metabolism in Rats after Laminectomy and Acute Compression Injury

Abstract

Many data are available concerning spinal cord blood flow (SCBF) and metabolism on various models and timing after spinal cord injury, however, detailed information on their exact relationship in the same injury model is lacking. This relationship is a crucial factor in the understanding of the pathophysiology of spinal cord trauma.Rats were subjected to lumbar laminectomy or lumbar spinal cord compression trauma. 3 hours later, changes in SCBF were evaluated autoradiographically and changes in ATP, glucose and lactate levels were analyzed using substrate-specific bioluminescence techniques. Measurements were performed at the lesion site (segment L4), adjacent segments (L3 and L5) and at remote thoracic segments (Th8 to Th9).Laminectomy alone did not change SCBF, both in thoracic and lumbar segments. In contrast, ATP levels were significantly reduced and lactate levels were increased at the lesion site and in adjacent lumbar segments at 3 hours after laminectomy, whereas glucose levels were not significantly changed. In animals subjected to additional compression trauma, SCBF was significantly reduced in segments L3, L4 and L5 paralleled by a significant ATP reduction and lactate increase. Glucose levels did not differ significantly from controls 3 hours after compression injury. This metabolic profile was also reflected in the remote thoracic segments. In contrast, SCBF was not reduced in thoracic segments of traumatized animals.The observation that ATP was already significantly reduced and lactate increased in laminectomized segments and in remote thoracic regions after trauma signals that metabolic changes are sensitive indicators to spinal stress. The fact that posttraumatic metabolic profile differs from the pattern of hemodynamic and metabolic changes induced by ischemia, suggests posttraumatic mediators may be involved in the different regulation of the energy producing machinery.

Stress-Resistant Neural Stem Cells Positively Influence Regional Energy Metabolism After Spinal Cord Injury in Mice

“…This metabolic pattern, typically seen in the brain after common carotid artery occlusion (Paschen et al 1983), was also described in the spinal cord compression injury model (Anderson et al 1980;Mautes et al 2000;Zhang et al 1993). The present results show a more complex situation.…”

“…Intensities were measured by determining optical density (OD). The bioluminescence was shown to correlate linearly with substrate concentrations measured quantitatively in tissue extracts using conventional enzymatic-fluorometric techniques (Mautes et al 2000). This bioluminescence approach measured the total level of the metabolites without distinguishing between endogenous and transplanted cells at the lesion site.…”

“…Analysis of energy metabolites by bioluminescence technique was performed as described (Mautes et al 2000(Mautes et al , 2001. Briefly, spinal cords were removed out of the vertebrae in a cold box at −20°C.…”