摘要Objective:To investigate the expression of Caspase-3 and Hsp70 in rabbits after severe traumatic brain injury (TBI) and to explore the feasibility of its application in estimation of injury time in forensic medicine.Methods:A rabbit model of heavy TBI was developed by high velocity impact on the parietal bone with an iron stick.Totally 8 healthy adult New Zealand white rabbits were randomly divided into control group (n=2) and injury group (n=6).Four hours after injury,tissue specimens from the parietal lobe,temporal lobe,occipital lobe,cerebellum and brainstem were harvested to detect the expression of Hsp70 and Caspase-3 by immunohistochemistry.Besides,the gray values of cells positive for Hsp70 and Caspase-3 were analyzed with an image analyzer.Results:Immunohistochemistry staining demonstrated a low level of Caspase-3 and Hsp70 expression in normal control group.While in injury group,both the Caspase-3and Hsp70 expression was significantly elevated (P＜0.05).Positive cells gathered around the lesion focus.Occipital lobe and cerebellum had fewer positive cells while temporal and brainstem had the fewest.Conclusion:The expression of Caspase-3 and Hsp70 at an early stage following severe TBI is characteristic and can be applied to estimate the time of injury.