Catecholamine levels in the injured spinal cord of monkeys.

The authors report a study of catecholamine levels in the spinal cords of monkeys following a 300 gm-cm blow to the midthoracic spinal cord. There was a progressive decrease in norepinephrine (NE) activity as a first-order process with a half-life of 6.4 hours. The NE activity in injured tissue never exceeded control levels, which remained unchanged both above and below the injured segment. Dopamine activity remained unchanged in the injured tissue as well as in control segments above and below the area of trauma for the first hour.