| Objective (1) to establish the model of rat electrical injury in low voltage for probing mechanism of electric death.(2) to find the differences of specific stain between the postmortem skin and that before death, and make sure whether it can be used to the identification of electrical injury.(3) to detect the expression of protein Jun in the rat's brain after electrical injury, find the differences of them between the postmortem and that before death, and make sure whether it can be used to the identification of electrical injury.Methods (1)60 wistar rats (200±10g) are divided into 3 groups at random. There are 10 rats in ex-experiment group,40 rats in experiment group and 10 rats in control group. To grope the electrical injury time and the interval,and to supervise the change of ECG with BL420E+ system.(2) 18 wistar rats (200±10g) are divided into 3 groups at random. There are 6 rats in every group. Operate electrical experiment, take skin tissue for HE staining, Mowory staining and Alcian blue-nuclear red staining, then detective the slide under microscope.(3) 60 rats (200±10g) are used in the experiment. They are divided into 2 groups, including the group of experiment group and control group; The former consists of the executing group of 1h,2h,4h,8h after electrical injury; the instantaneous group after electrical death; the postmortem group in 15min,30min,1h;and control groups. The time of electrical shock lasts for 2.7s while the interval time is 0.5s in electric injury group. Take the whole brain for the experiment, and take the skin tissue of electrical location,4% neutral formalin fixation for 24h,paraffin imbedding,cutting sheets about 4um. Immunohistochemistry staining with AEC: do the staining according to the kit instruction, and the effective density of first antibody is 1: 100.Take PBS solution for the blank control.Results (1)HE staining in skin tissue of rat: There are some obvious differences of HE staining between the electrical injury group before death and the control group. The obvious changes are collagen fibers in derma swell and homogenize. Basilar membrane cell nucleus in the middle of injury place elongate in length wise. This phenomenon also can be found in electrical injury group after death, especially in skin tissue. But we don't find apparent differences between the group before and after death.(2) Mowory(ABPAS) staining in the skin tissue of rat: Both the group before death and the group after death have obvious differences comparing to the control group. In the group after death, collagen fibers and elastic fibers maintain these own morphous,the nucleus are stained with blue. There are no obvious phenomenon of clarifixation.Alcian blue-nuclear red staining in the skin tissue of rat: In the group before death, clarifixation phenomenon of collagen fibers and elastic fibers in the papillary layer and reticular layer of dermis are very obvious. We can also find a lot of red cell nucleus of fibers in the reticular layer. In the group after death, collagen fibers and elastic fibers maintain these own morphous,the nucleus are stained with red .There are no obvious phenomenon of clarifixation. Almost all the cases in the electrical group before death have apparent differences from electrical injury group after death.(3) We can find c-jun protein strong positive expression in cerebral cortex and hippocamp in the electrical groups before death, and it come to the peak in 4h.There are little expression in 8h.The tissues in the group after death and the control group have no c-jun protein expression.Conclusion (1) the model have obvious electrical injury features, and can be used to the forensic research of electrical injury.(2) c-jun protein can be an indicator that can be used to the identification of electrical death. There are some difference in skin between postmortem electric injury and electric injury before death. So it can be an auxiliary indicator in electric injury assessment.
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