Thyrotropin-releasing hormone in experimental spinal injury: dose response and late treatment.

Early treatment with thyrotropin-releasing hormone (TRH) at high doses improves neurologic recovery from experimental spinal injury in cats. We have now compared the effects of TRH dose and time of treatment on neurologic outcome. TRH-treated animals showed better motor recovery than saline controls; effects were dose-related (between 0.02 mg/kg/hr and 2.0 mg/kg/hr), with significant effects even at the lowest dose. Cats treated at 24 hours after injury also improved significantly. These findings provide additional support for TRH trials in human spinal injury and suggest that even late treatment may be effective.