Abstract

BACKGROUND AND OBJECTIVE: Human umbilical cord blood (HUCB) is a rich source of stem cells. The aim of this study was the investigation of the therapeutic effects of these cells on cerebral ischemia in rat. METHODS: This study was carried out on 30 male Wistar rats (100-150 g). They were divided into three groups. Firstly, to create a laboratory model of ischemic stroke, right carotid artery of animals was occluded for 30 minutes in two groups of experimental and sham. Then, mononuclear cells of cord blood were isolated and labeled using bromodeoxyuridine (BrdU) and then 2×105 cells were injected into the experimental group via the tail vein seven day after surgery. Rats in sham group didn't receive any injection. Control group considered as intact animals. The animals were evaluated for 14 days with modified limb placing and corner turn tests. The transplanted HUCB cells were also detected by immunohistochemistry. FINDINGS: Seven days after surgery, there was a significant recovery in the behavioral performance in the experimental group (12.7± 0.26) compared with sham group (10±0.4) and this significant difference continued by the day 14 (15.3±0.31 vs. 11.9±0.53, p<0.05). Postural and motor asymmetries, at the days 7 and 14 the experimental group showed a significant decrease in the percentage of right turns in comparison to the sham group (75±3.07 and 59±3.14 vs. 96±2.21 and 97±2.13, p<0.05). In addition, injured volume measurements disclosed a significant decrease in the experimental group compared with sham group (p<0.05). CONCLUSION: Intravenously transplanted HUCB stem cell can accelerate neurological function recovery and diminish the lesion size after the hypoxic ischemia. Thus these cells may provide a potential cell candidate for cellbased therapy in stroke.