Study of neuroprotection of mild hypothermia combined with erythropoietin in traumatic brain injury rats

Objective To study the protective mechanism of mild hypothermia (MHT) and erythropoietin (EPO) therapy on traumatic brain injury (TBI) rats. Methods Eighty male Wistar rats were randomly divided into sham-operated group (Sham), normothermic treatment following TBI group (NT), mild hypothermia group (MHT), EPO group (EPO), and combined group (MHT+ EPO), respectively. The TBI animal models were established according to fluid percussion impact (FPI) method. The neurological deficit was evaluated using a modified neurological severity score (mNSS) at 48 h after FPI. The changes of brain water content and permeability of blood-brain barrier were measured by the methods of wet and dry weight and Evans blue stain. The sizes of injury lesion were evaluated by hematoxylin and eosin (HE) stain. Western blotting and RT-PCR were used to analyze the expression of Claudin-5. Results Both MHT and EPO treatment lessened the neurological deficit scores. The brain water content, lesion size and attenuate BBB permeability and the expression of Claudin-5 were observed(P<0.05). Conclusions Both MHT treatment and EPO treatment could express neuroprotective effect for TBI rats. This protective effect against TBI might be achieved by upregulation of Claudin-5. Key words: Craniocerebral trauma; Hypothermia, induced; Erythropoietin; Rats