RESUMO
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.