The Neuroprotective Effects Of Apelin-36 On Neonatal Sprague-Dawley Rats With Periventricular Leukomalacia

Objective: To investigate the effect of Apelin-36 on the expression of late oligodendrocyte precursor marker O4(O4)and immature oligodendrocyte marker O1(O1)in the periventricular leukomalacia(PVL)model of neonatal SD rats,and to explore its neuroprotective effect.Methods: The periventricular leukomalacia model was made by ligation the left common carotid artery of 3-day-old neonatal SD rats and then breathing 92%N2 +8%O2 for one hour.The PVL model of newborn rats were randomly divided into the PVL model group,apelin trial group,and the sham operation group was made also.HE staining was used to observe the pathological changes of white matter around the ventricle at 7 days,14 days and 21 days after birth.The expression of O4 and O1 in the white matter around the ventricle was detected by immunohistochemistry.Results:1.Pathological changes in the white matter around the ventricle of three groupsAt 7 days after birth,the pathological manifestation in periventricular white matter of PVL model group were observed,white matter damage including white matter loose,edema,necrosis,irregular of cell arrangement,glial cell proliferation and left lateral ventricle dilatation.At day 14 and day 21,the mainly pathological lesion of PVL model group represented proliferation of collagen fibers,pectin scar,liquefaction necrosis in alba and softening lesion,in addition,the left lateral ventricle became larger,In the apelin trial group,at 7 days,14 days,21 days,the pathological manifestation of the periventricular white matter similar to the PVL model group,but the degree of damage were mild than the PVL model group,the lateral ventricle enlargement become smaller compare with the PVL model group.There was no abnormal pathological changes at each time point in the sham operation group.2.The immature oligodendrocyte marker O1 expression in periventricular white matter of three groupsThe expression of O1 in periventricular white matter of the PVL model group was the least in three group at 7 days,14 days and 21 days after birth,and the apelin trial group was middle,the sham operation group was maximum,there was a significant difference between the two groups in each other(P <0.05).The expression of O1 decreased gradually with the increase of age at 7 days,14 days and 21 days after birth in each groups,analysis of variance showed that there was significant difference(P <0.05).3.The expression of late oligodendrocyte precursor marker O4 in periventricular white matter of three groupsAt day 7,day 14 and day21 the expression of O4 in the white matter around the ventricle of the PVL model group was the minimum in three groups,next was the apelin trial group,the sham operation group was maximum,at the same time point,there was a significant difference between the two groups in each other(P <0.05).The expression of O1 in each group was decreased gradually at 7 days,14 days and 21 days after birth,analysis of variance showed that there was significant difference(P <0.05).Conclusion:1.Apelin-36 can relieve the degree of loose,edema,reduce the formation of glial scar in the white matter around the ventricle,and diminish the degree of lateral ventricle enlargement in PVL model of neonatal SD rat,its suggested that apelin-36 may play an important role in neuroprotective effect.2.Apelin-36 can promote the expression of O1 and O4 in white matter of neonatal SD rat with PVL,its suggested apelin-36 relieve the damage and loss of late oligodendrocyte precursor and immature oligodendrocytes due to hypoxia-ischemia play a part in the neuroprotective effect for neonatal SD rat with PVL.