Expression of Hsp70 and Caspase-3 in rabbits after se- vere traumatic brain injury

Objective： To investigate the expres- sion of Caspase-3 and Hsp70 in rabbits after severe trau- matic brain injury （TBI） and to explore the feasibility of its application in estimation of injury time in forensic medicine. Methods： Arabbit 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 HspT0 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-3 and 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 HspT0 at an early stage following severe TBI is characteristic and can be applied to estimate the time of injury.