[Changes of microcirculation dynamics in the formation of edema following spinal compression injury in rabbits]

The changes in microcirculation dynamics were investigated, after giving acute compression to the spinal cord in rabbits. When the 8th thoracic cord was compressed for one minute with a plummet weighing 50g, paraparesis occurred, from which the animals could recovered within two weeks. The blood flow at the compressed region, determined by the hydrogen clearance method, one hour after the injury was increased to 154% of the pre-injury level, while the flow was reduced by 22% six hours later. The vascular permeability, estimated by the fluorescein method, was found to be 3.3 times greater in the injured animals than that in controls only at one hour after compression. The water contents of the spinal cord, determined by the dry weight method, were gradually increased up to six hours. These results suggest that vasogenic edema due to the primary damage to the vascular system in the spinal cord may occur within one hour of the compression and cytotoxic edema may appear six hours later.