Role of oxygen free radical-mitochondria signal pathway in Edaravone treating traumatic brain injury / 中华创伤杂志

ABSTRACT

Objective To investigate the expression of apoptosis-related proteins in rat cerebral cortex following traumatic brain injuries(TBI)and discuss the role of oxygen free radical-mitochondria signal pathway in Edaravone treating TBI.Methods A total of 180 male adult Sprague-Dawley rats were randomly divided into TBI group,Edaravone treatment group and control group.Each group was divided into six subgroups at 1,3,6,24,48 and 72 hours after TBI.Edaravone treatment group was injected with Edaravone(10 mg/kg)and the other two groups injected with the same volume of 0.9%normal saline.The pathological change in the rat cortex following TBI was observed with HE staining.At different time points,the expressions of Cytc,Bcl-2 and Bax in rat cortex as well as cell apoptosis and MDA change were observed by means of immunohistechemistry,TUNEL and TAB.Results HE staining showed scattered degenerated and necrotic neurous in cerebral cortex six hours after neuron injury,which peaked at 24 hours.Compared with control group,intermediate product MDA of free radical was increased six hours after TBI and peaked at 48 hours in Edaravone treatment group,which was lower than TBI group especially at 24,48 and 72 hours(P＜0.05).Compared with control group,the immunity reaction of Cytc positive cells inereased at six hours and peaked at 24 hours in TBI group,with statistical difference at 3,6,24,48 and 72 hours(P＜0.05).Compared with TBI group,the immunity reaction of Cyte positive cells was decreased obviously at 24,48 and 72 hours in Edaravone treatment group.Hyperexcitability of Bcl-2 after TBI reached peak at 3 hours and decreased gradually.But the expression of Bax was increased gradually after TBI and peaked at 48 hours,when Bax/Bcl-2 reached peak too.Folowing TBI,TUNEL positive cells increased gradually and reached peak at 48 hours,with mainly type Ⅰ TUNEL cells before 24 hours and typeⅡTUNEL cells after 24 hours.Conclusions There exist necrosis and apoptosis of nerve cells in cortex after TBI,especially apoptosis.Oxygen free radical mitochondria is one of the signal transduction pathways of nerve cell apoptosis following TBI.Edaravone exerts certain therapeutic effect on TBI.