EFFECTS OF TRH AND HIGH-DOSE CORTICOSTEROID-THERAPY ON EVOKED-POTENTIALS, AND TISSUE NA+, K+ AND WATER-CONTENT IN EXPERIMENTAL SPINAL-INJURY

The therapeutic effects of continuous infusion of thyrotropin-releasing hormone (TRH) and methylprednisolone (MP) in experimental spinal cord injury were studied in Swiss albino rats. Thirty rats received a 53-g clip-compression injury on the cord at T1, then were allocated randomly and blindly to one of three treatment groups (ten animals in each): (1) control; received equal volumes of saline solution; (2) MP; received 30 mg/kg methylprednisolone i.v. 1 h after trauma, followed by infusion of 5.4 mg/kg/per hour i.v. for 3 h. (3) TRH: received 2 mg/kg TRH i.v. 1 h after trauma, followed by infusion of 1 mg/kg/per hour i.v. for 3h. MP and TRH treatments significantly improved somatosensory-evoked potentials (SEPs; P < 0.001). Both treatments significantly reduced water content, decreased Na+ content and increased the K+ content of the cord segment that included the centre of the impact (P < 0.01). Our data provide evidence for the beneficial effects of high-dose corticosteroid and TRH in promoting electrophysiological recovery and preserving spinal cord tissue following experimental injury.