Effects of a Single Intravenous Glucocorticoid Dose on Biogenic Amine Levels in Cat Lumbar Spinal Cord

Abstract: The effects of a single large intravenous dose of methylprednisolone on the steady state levels of dopamine, norepinephrine, and 5‐hydroxytryptamine in cat lumbar spinal cord, as a function of dose (15, 30, or 90 mg/kg) and time (1 or 24 h) after administration, were examined by high performance liquid chromatography with electrochemical detection. Methylprednisolone produced a dose‐related increase in the levels of dopamine and 5‐hydroxytryptamine, but not norepinephrine, measured at 1 h. The effect of the single glucocorticoid dose was biphasic, however, as measurement of the three amines at 24 h showed each to be depressed below the levels found in untreated animals. The possible mechanistic basis and the significance of these glucocorticoid effects are discussed.