Treatment of experimental spinal cord injury with TRH, naloxone, and dexamethasone

Comparison of thyrotropin-releasing hormone (TRH), naloxone, and dexamethasone treatments in experimental spinal cord injury was studied in albino rats. Animals were made paraplegic by the application clip method of Rivlin and Tator. Treatment was administered intraperitoneally as a bolus injection in two doses at 45 and 120 minutes each after the injury. Animals were allocated randomly to one of four experimental treatment groups: (1) TRH (0.6 mg of TRH per dose) (2) naloxone (0.8 mg per dose), (3) dexamethasone (0.6 mg per dose), and (4) saline. Neurologic recovery was assessed by the inclined plane method, and cavitation size of the cord and of the pyramidal tract was examined under the light microscope. Results show that TRH and naloxone are therapeutically beneficial in the treatment of spinal cord injury, and that dexamethasone is ineffective.