The Effect Of Ginsenoside Rd On The Expression Of O4 And O1 In The White Matter Of Neonatal Rat Model Of Periventricular Leukomalacia

Objective:To investigate the effect of Ginsenoside Rd on the expression of O4 and O1 in the white matter of neonatal rat model of periventricular leukomalacia（PVL）by establish the neonatal rats model of PVL and detecting the expression of O4 and O1 in the white matter.Methods:Set up the PVL model of SD rats by isolating and ligating the left common carotid artery in 3-day-old newborn SD rats that were later set to inhale mixed gas of92%N₂+8%O₂ for 1 hour.The PVL rats were randomly divided into PVL model group,GSRd trial group and the sham operation group.Eight rats selected randomly in each groups were sacrificed on day 3,day 7 and day 14 after operation.Pathological change of brain was observed by HE staining,and the expression of O4 and O1 were detected by immunohistochemistry in the white matter around the cerebral ventricle of three groups.Results:1.Pathological changes of brain tissues with HE staining of three groupsThe lesions of the PVL model group and GSRd trial group mainly occurred in the periventricular white matter,corpus callosum and hippocampus.The degree of damage in cerebral cortex was mild.There were no anomalous pathological change at each time point in the sham operation group.At day 3 after operation,the PVL model group appeared loose structure of white matter,cell edema,necrosis,irregular of cell arrangement,microglia cell hyperplasia.At day 7,the nerve cells were obviously edematous,microglia cells proliferation and cystic necrosis were found and the left lateral ventricle was slightly enlarged.At day 14,the microglial cell hyperplasia and glial scar were observed obviously,white matter around the cerebral ventricle attenuated and the lateral ventricle was obviously enlarged.Compared with the PVL model group,the changes of brain tissue morphopathology in GSRd trial group were mild,and the degree of left lateral ventricle enlargement was alleviated.No colloid scar formation was observed.2.Immunohistochemical staining in the white matter of periventricular region2.1 Expression of O4 in the white matter around ventricleAt each time point,the expression of O4 in white matter around the cerebral ventricle was the lowest in the PVL model group,followed by the GSRd trial group,and the sham operation group had the highest expression.The difference was statistically significant among three groups（P<0.05）.In comparison of different time points in the same group,with the increase of age on day 3,day 7 and day 14 after operation,the expression of O4 decreased gradually and significant differences were found between groups（P<0.05）.2.2 Expression of O1 in the white matter around ventricleAt the same time point,the expression of O1 in white matter around cerebral ventricle of the PVL model group was the minimum among three groups,the sham operation group was maximum and the GSRd trial group was middle.The difference was statistically significant among three groups（P<0.05）.In comparison of different time points in the same group,the expression of O4 decreased gradually with the increase of age on day 3,day 7 and day 14 after operation and there were significant differences among three groups（P<0.05）.Conclusion:1.Ginsenoside Rd can relieve the degree of loose,edema and necrosis of nerve cells in periventricular white matter and lessen the extent of ventricular enlargement in PVL model of newborn SD rats,suggesting that Ginsenoside Rd has some neuroprotective effects.2.Ginsenoside Rd can promote the expression of O4 and O1 in periventricular white matter of the PVL model and mitigate the damage and loss of late oligodendrocyte precursor cells and immature oligodendrocytes,which indicates Ginsenoside Rd may promote the differentiation and maturation in various stage of oligodendrocyte.