[Effect of tacrolimus on growth-associated protein-43 expression in the hippocampus of neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE

Immunosuppressant tacrolimus (FK506) has shown neuroprotective effects on hypoxic-ischemic brain damage (HIBD) in the adult animal model. This study investigated whether FK506 has a protection against HIBD in neonatal rats by examining growthjassociated protein-43 (GAP-43) expression in the hippocampus.

METHODS

Ninety-six seven-day-old Sprague-Dawley rats were randomly divided into three groups: sham-operation, HIBD and FK506 intervention group. HIBD was induced in the later two groups. The FK506 intervention group was intraperitoneally injected with FK506 immediately after HIBD, at a dosage of 1 mg/kg daily, for three days. The HIBD group was injected with normal saline. Immunohistochemical technical was applied to examine GAP-43 expression in the hippocampus 24 and 72 hrs and 7 and 14 days after HIBD.

RESULTS

Compared with the HIBD group, hematoxylin-eosin staining showed attenuated neuronal necrosis in the FK506 intervention group. In the HIBD group, the expression of GAP-43 increased significantly 72 hrs, and 7 and 14 days after HIBD compared with that in the sham-operation group. The GAP-43 expression in the FK506 intervention group was significantly higher than that in the HIBD group 72 hrs and 7 days after HIBD.

CONCLUSIONS

FK506 might have neuroprotective effects against HIBD in neonatal rats.