Influence of retinoic acid on expression of nestin of endogenous neural stem cells in ischemic sides of newborn rats with hypoxic-ischemic brain injury

[Objective] To investigate influence of retinoic acid on expression of nestin of endogenous neural stem cells in ischemic sides of newborn rats with hypoxic-ischemic brain damage(HIBD). [Methods] Totally 56 neonatal rats aged 7 d were randomly divided into two groups(hypoxic-ischemic NS control group and RA-treated group,group with 28 rats in each). According to the time of sacrefice, 28 rats of every group were further divided randomly into four groups including third day (3 d) , the seventh day (7 d) , the fourteenth day(14 d)and the twenty-first day (21 d) , with 7 rats in each subgroup.The HIBD mode establish that left common carotid artery of the neonatal rats in hypoxic-ischemic group was ligated and subjected to inhalation of 8% oxygen for 2.5 h.intraperitoneal injection RA in treated group and NS in NS control group.NSCs from brain tissues of the rats of the two groups were determined with immunohistochemicalmethod under light microscope.Nestin cell mark NSCs. [Results] In RA-treated group,neuroiogic impairment score was significantly more than in the control groups at 3、7、14 and 21 d;there were positive nestin cells in the cortex and hippocampus at 3、7、14 d and 21 d,peaked at 3、7 d.the numbers of NSCs fall off from rats age accrete;In RA- treated group,the numbers of NSCs was significantly more than in the control groups,especiallythe was very significantly at 7、14 d and 21 d(P0.01). [Conclusion] RA can promote and keep high expression of the positive nestin of endogenous neural stem cells in ischemic sides of newborn rats with HIBD.