OBJECTIVETo study the protective effects of nerve growth factor (NGF) and Danshen on hippocampal neurons in gerbils (Meriones unguiculatus) with global ischemia-reperfusion injury.

METHODSGlobal ischemia-reperfusion model was established in 54 male Z:ZCLA gerbils by occlusion of the bilateral carotid arteries. The animal models were randomized into 3 groups to receive treatment with normal saline, NGF, and Danshen 30 min after the reperfusion. At 6 h, 3 and 7 days after the reperfusion, the survival of the hippocampal CA1 pyramidal neurons was observed using optical and electron microscopy, and immunohistochemistry was employed to detect the expressions of Bcl-2 and Bax in the neurons.

RESULTSNeuronal apoptosis was not observed in the hippocampus 6 h after the reperfusion, but at 3 and 7 days, the number of apoptotic neurons increased significantly in the CA1 region. Compared with normal saline, treatments with NGF and Danshen both significantly reduced the number of apoptotic neurons at 3 and 7 days. The number of apoptotic neurons showed no significant difference between NGF and Danshen treatment groups at 3 days, but at 7 days, the apoptotic cell number was significantly lower in NGF group (P<0.05). Bcl-2 expression was the highest in NGF group, and its highest expression occurred at 6 h after the reperfusion; Bax expression was detected in saline group, and underwent no significant changes with the passage of time.

CONCLUSIONBoth NGF and Danshen show protective effects against global ischemia-reperfusion injury. NGF has a stronger protective effect than Danshen, and this finding provides experimental evidence for selecting appropriate protective agents in the treatment of ischemic brain damage.