OBJECTIVETo explore the neuroprotective effect of FK506 on acute spinal cord injury in dogs.

METHODSAcute spinal cord injury model was made with the Allen technique. Animals were randomly divided into 3 groups. Group A (n = 8) was the control group and received operation but no therapy, while group B and C (n = 8) received a single dose of FK506 (0.18 mg/kg and 0.3 mg/kg, respectively) administered with an arterial duct 2 h after spinal cord injury (SCI). Spine MRI, neurological function, histopathological examination of injured spinal cord and immunohistochemical examination of expression of NF(200) in neurons and GFAP in astrocytes were assessed at certain time after injury.

RESULTSNeurological function score of group C and B was better than that of group A (P < 0.05), with significance between group C and A, while no significance between group B and A statistically. The signal scope of spinal cord injury on MRI in group C was the smallest among all the groups, and the signal scope in group B was smaller than that in group A, which was directively associated with the neurological outcome. The expression of NF and GFAP was significantly higher in group C than in group A (P < 0.05), but without statistical significance between group B and A.

CONCLUSIONLocal administration of FK506 (0.3 mg/kg) possesses neuroprotective effect on acute spinal cord injury, which can improve neurological function recovery and attenuate secondary spinal cord injury. Local administration of FK506 possesses a dosage-effect relation.