Acute enhancement of spinal cord synaptosomal (Na+ + K+)-ATPase activity in cats following intravenous methylprednisolone.

The acute intravenous administration of high doses of methylprednisolone sodium succinate (15-90 mg/kg) to cats enhanced (Na+ + K+)-ATPase activity as much as 2-fold in synaptosomes prepared from lumbar spinal cord removed following drug administration. The effect was apparent within 5 min and was statistically significant at 1 h following a single injection of methylprednisolone 90 mg/kg. (Na+ + K+)-ATPase activity had returned to control levels by 24 h post-injection. The implication of these findings to the treatment of spinal cord trauma and the reported neurophysiological effects of glucocorticoids are discussed.