Effects of intracarotid administration of human cord blood mononuclear cells on expressions of brain-derived neurotrophic factor and nerve growth factor in rats with vascular dementia

Objective To explore the effects of intracarotid administration of human cord blood mononuclear cells (HCMNCs) on the expressions of brain-derived neurotrophic factor (BDNF)and nerve growth factor (NGF) and the learning-memory abilities in the vascular dementia (VD) rats.Methods The VD rat model was established by modified Pulsinellis 4-vessel occlusion (4 VO). The rats were randomly divided into a control group, a model group and a treatment group. The three groups were observed at three time points: 2 w, 4 w and 8 w, twelve rats in each time point. HCMNCs were isolated from human umbilical cord blood in vitro. The treatment group received intracarotid infusion of 3×106 HCMNCs which were prelabeled with BrdU in vitro. The learning-memory abilities and the contents of BDNF and NGF were observed at 2, 4 and 8 weeks by computerized shuttle-training case and enzyme-linked immunosorbent assay (ELISA). Results Active avoidance response (AAR) ratio in the model group was significantly decreased compared with the control (P＜0.01), and the treatment group was significantly higher than the model group (P＜0.01). The contents of BDNF and NGF in the model group was significantly higher than those in the control, increased to the highest level at 4 weeks, and then decreased at 8 weeks, but compared with that at 2, 4 weeks, significant difference was found (P＜0.05).Com pared with the model group, the contents of BDNF and NGF in the treatment group were significantly increased after infusion with HCMNCs, increased to the highest level at 4 weeks (P＜0.05,P＜0.01), and then decreased a little at 8 weeks but maintained the high level that was not significantly different from that at 2, 4 weeks (P＞0.05). Conclusions Intracarotid administration of HCMNCs significantly improves the learning-memory abilities, possibly through increasing the contents of BDNF and NGF in the VD rats. Key words: Human cord blood mononuclear cells; Vascular dementia; Pulsinellis 4-vessel occlusion;  Intracarotid artery;  Brain-derived neurotrophic factor; Nerve growth factor