Spinal cord repair: is tissue oxygenation an important variable?

We have demonstrated the reliability and feasibility of making PtO2 recordings from graft and host tissue in the injured spinal cord. The data suggest that the oxygen microenvironment of developing graft and host spinal tissue is clearly different from that found in normal spinal tissue or in transplants that have not survived or integrated well. These same constraints seem to apply to cavitation in developing grafts and poorly developed graft/host interfaces. The similarity between these findings and those from previous studies in other fetal vertebrates suggests that oxygen tensions in the spinal cord probably reflect the developmental status of the regenerating tissue. Our future studies will seek to define the relationship between anatomical development of transplant tissue and these functional (PtO2, microvascular development and tissue metabolism) indicators of graft development. These investigations should also provide a background for those later studies which seek to establish the mechanisms by which these relationships come about i.e. oxygen consumption of host/transplant tissue, blood flow to transplants, studies of glycolytic metabolism (2-DG autoradiography), etc. In this way, we can begin to understand the role of tissue metabolism in graft-mediated repair.