Effects of tacrolimus and erythropoietin in experimental spinal cord lesion in rats: functional and histological evaluation

STUDY DESIGN: Experimental study with rats. OBJECTIVE: To evaluate functional and histological effects of tacrolimus (FK 506) and erythropoietin (EPO) after experimental spinal cord contusion injury (SCI). SETTING: Brazil. METHODS: Wistar rats (n=60) were submitted to SCI with the NYU Impactor system. The control group received saline; the EPO group received EPO; the group EPO+FK 506 received EPO associated with tacrolimus and the group FK 506 received tacrolimus only. The Sham group underwent SCI, but did not receive any drug. Locomotor function was evaluated after SCI by BBB (Basso, Beattie and Bresnahan) weekly and by the motor-evoked potential test in 42 days. The spinal cord was histologically evaluated. RESULTS: There was a significant difference between treated and the control groups from the seventh day on for BBB scores, with no difference between the groups EPO and EPO+FK 506 by the end of the study. There were significant differences between groups for necrosis and bleeding, but not for hiperemia, degeneration and cellular infiltrate. Axon neuron count was different between all groups (P=0.001), between EPO+FK 506 and FK 506 (P=0.011) and between EPO+FK 506 and Sham (P=0.002). Amplitude was significantly different between all groups except between control and sham. For latency, there was no difference. CONCLUSIONS: This study did not reveal significant differences in the recovery of locomotor function, or in the histological and electrophysiological analysis in animals treated with EPO and tacrolimus after thoracic SCI.