Morphohistological changes in a focus of spinal cord trauma have a phasic character, with a period of primary lesions (5-30 min after traumatization) and a period of secondary lesions (1-23 h after traumatization). 2. Variation of transport enzyme activities in the walls of the microvessels of the traumatized spinal cord is characterized by an undulating course and by asynchrony of the peaks of Mg-dependent ATPase and alkaline phosphatase activity. 3. With reference to the rapid drop in the given enzyme activities and to progressive necrotic changes in the traumatized spinal cord, it is desirable that the cord circulation should be corrected within the first few hours after traumatization.