Effect of mouse nerve growth factor on the expression of glial fibrillary acidic protein in hippocampus of neonatal rats with hypoxic-ischemic brain damage

The present study aimed to investigate the influence of mouse nerve growth factor (mNGF) on glial fibrillary acidic protein (GFAP) expression in neonatal rats with hypoxic-ischemic brain damage (HIBD). A total of 60 7-day-old neonatal rats were randomly divided into control, HIBD and mNGF groups (n=20). The rats in the mNGF group were injected intramuscularly with mNGF once a day for 5 days. Each group was randomly divided into a day 7 subgroup and a day 14 subgroup according to the time of sacrifice. After the rats were sacrificed, the expression of GFAP in the hippocampus in the three groups was confirmed by immunohistochemical analysis. The results revealed that the expression level of GFAP in the ischemic side of the hippocampus in the mNGF and HIBD groups was higher compared with that in the control group at days 7 and 14 after surgery, respectively (P<0.01). GFAP-positive cells were mainly distributed in the ischemic side of the hippocampal dentate gyrus (DG) region in the mNGF group while in the HIBD group they were in the ischemic side of the hippocampal CA1 region. Compared with day 7, the expression of GFAP in the ischemic side of the hippocampus in the mNGF group increased at 14 days (P<0.01), but decreased in the HIBD group (P<0.01); however, this was still higher than that in the control group (P<0.01). This study revealed that mNGF increases the expression of GFAP in the hippocampus of neonatal rats with HIBD and therefore may have a role in the repair of HIBD.