Role of melatonin for repairing the periventricular white matter damage due to hypoxia-ischemia in the developing brain of rat / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the protective effect of melatonin and its possible mechanism for repairing in the immature white matter damage due to brain hypoxia-ischemia (HI).Methods Forty-eight three-day SD rats after birth were randomly divided into 3 groupssham-operated(SHAM) group,HI group and melatonin treatment(MT) group.Periventricular white matter damage (PWMD) to animal models were estabished according to Rice modeling.MT group was treated with melatonin pre-operatively,immediately postoperation,1 hour postoperation and 24 hours postoperation via intraperitoneal injection,and the other groups were injected with the same volume of dissolvent.The rats were executed by decollation after 2 days and 14 days.The histological changes in periventricular white matter were observed by HE staining and immunohistochemistry.Results For the 3 groups,the structure in ope-ration side of the white matter in the peripheral ventricles of the brain 2 days postoperation were significant different (P ＜0.05).The O4 positive cells decreased one by one/greatest in the SHAM group[(75.548 ± 7.333)/hpf] followed by MT group [(59.971 ± 3.635)/hpf],and HI group [(40.511 ± 2.848)/hpf] (P ＜ 0.05).The expression of Casepase-3 increased in the SHAM group (107.724 ± 10.266),MT group (132.289 ± 8.537),and HI group (202.168 ± 14.367),and the difference was statically significant (P ＜ 0.05).Ventricular index was greater in operation side of the white matter in the peripheral ventricles of the 14-day-brain in the SHAM group(0.928 ±0.063),MT group (1.813 ± 0.110),HI group (2.752 ± 0.201),increasingly,while absorbance value of myelin basic protein decreased one by one in sequence(39.504 ± 1.673,21.729 ± 1.614,11.344 ± 1.118).Conclusions MT plays a role in protecting the periventricular white matter via inhibiting the apoptosis of oligodendrocyte progenitor cell,and thus benefits the PWMD.