Study of tumor necrosis factor-alpha and nuclear factor-kappa B expression in perihematoma region of experimental intracerebral hemorrhage rats after skull local mild hypothermia

Objective To produce the experimental intracerebral hemorrhage(ICH)model in rats and study the effect of skull local mild hypothermia on cytokines and transcription factors in tissue surrounding the hematoma of ICH.Methods The rat model of experimental ICH was made by the method of injection of autologous arterial blood into the caudate nucleus of Wistar rats.The rats were divided into 3 groups at random:the sham-operation group,the normothermia group and the mild hypothermia group.A head cooling therapeutic instrument was introduced into the mild hypothermia group immediately after the injection and then maintained mild hypothermia for 48hrs.The coronal slides of cerebral tissue were stained by HE and with rabbit polyclonals anti-TNFα,anti-NF-κB/p65 antibodies by immunohistochemical technique.The positive cells were counted for statistic analysis.Results The experimental ICH model in rats was successful.In the mild hypothermia group,the damage was less than the normothermia group.The expression of TNF-α and NF-κB sites of the normothermia group focused on the circumambience of the hematoma,cortex,callose,choroid plexus of the operated side.Compared with the sham-operation group,the quantity of positive cells had significant deviation(P0.01).The expressional level of NF-κB and TNF-α was also reduced in the mild hypothermia group(P0.05)compared with the normothermia group,with significant deviation.Conclusion It indicates the presence of inflammatory response in brain at acute stage of ICH.The method of skull local mild hypothermia can reduce the expression of TNF-α and NF-κB of cerebral tissues.It can inhibit inflammation after ICH by preventing the activation of NF-κB.So the treatment is helpful for neuroprotective.