Efeito da prednisona em lesão medular aguda experimental em ratos (Rattus novergicus).

Abstract

We develop a model to evaluate the effects of prednisone when applied at different time intervals after moderate and acute spinal cord injury. A pilot study using 10 Rattus novergicus allowed us to define a spinal cord injury protocol as 50.5g applied during five minutes with estereotoxic equipment. Later 25 rats were submitted to this protocol and randomly divided into five treatment groups: one group received placebo 8 hours after injury and the remaining four groups received prednisone eight, 24, 48 and 120 hours after injury. Prednisone was applied at 2 mg/Kg dosage during five days and progressively reduced until the 26th day. Animals were evaluated by motor capacity, proprioceptive positioning, searching ness reflex, inclined plan and sensibility to pain. Each rat was sacrificed 33 days after surgery for histopathology of the spinal cords that revealed degeneration of the rootlets, spinal cord necrosis and reactive gliosis, with no significant differences among treatment groups. Results for the various tests did not seem to be consistent and hence we could not conclude which treatment group was the best. Late administration of high dosages of prednisone to animals with acute spinal cord injury had no deleterious effects on neurological recovery