Abstract:

BACKGROUND: Insulin-like growth factor-1 (IGF-1) is a peptide hormone, it has been proved a promotion role on the proliferation of precursor cells.
OBJECTIVE: To explore the intravenous injection of IGF-1 on the proliferation, migration and differentiation of neural stem cells in rats after cerebral ischemia.
METHODS: Eight adult male SD rats were randomly divided into control group and experimental group, with 40 rats in each group. The rats in two groups were used to prepare models of focal cerebral ischemia using modified suture method, the rats in the experimental group were treated with tail vein injection of IGF-1, according to 100 μg/kg computation, the injection was given for 6 continuous days; in the control group, rats were given equal volume of saline. The rats were decapitated at 7, 14, 21, 28 days following intervention, respectively, and rats in each group were given intraperitoneal injection of the BrdU at 1 day before death. Immunohistochemistry and double staining were applied to detect the expressions of BrdU-positive cells, PSA-NCAM-positive cells, BrdU + PSA-NCAM double-positive cells, and BrdU + MAP2 double-positive cells.
RESULTS AND CONCLUSION: The number of BrdU-positive cells and PSA-NCAM positive cells reached the peak at 7 days after ischemia; BrdU + PSA-NCAM double-labeled-positive cells could be detected in ischemic bilateral subependymal zone and dentate gyrus, the number was the most at 7 days, then followed by a gradual decrease; the BrdU + MAP2 double-positive cells began to increase from 14 days, and then gradually increased along with the decrease of BrdU + PSA-NCAM double-positive expression, showing a reverse trend. Intravenous injection of IGF-1 can induce the proliferation, differentiation and migration of neural stem cells in rats following ischemic brain injury.