The Changes Of Postmortem Biomechanics Characteristic And Collagenous Fiber, Elastic Fiber On Rat Skin

Background and purpose: Estimating of time since death have been the most important and difficult work in forensic pathology for a long time. Previously people have studied postmortem changes of cadaver resulted from decomposition and autolysis to estimate the postmortem interval (PMI), and done better in estimating the short-term PMI than the long-term one. Being a kind of biology solid, skin have some biomechanics characteristic (viscosity). When a cadaver decomposition processed, skin was the latest part to be breakdown. The decomposition and autolysis of skin is supposed to change its histological structure and biomechanics characteristic. To establish a animal experimental model estimating the PMI, especially a long-term PMI, we studied the biomechanics characteristic and gross, histology (especially collagenous fiber and elastic fiber) changes of rat skin in different environmental condition and different PMI in this research, and found out the relationship between them as well as their correlation with PMI.Methods: Recording their body length and mass, fifty-four healthy female Sprague-Dawely rats were randomly divided into groups A and B. According to the time of drawing the materials after sacrificing, the former was subdivided into ten subgroups at 0h, 6h, 12h,1d, 2d, 3d, 4d, 5d, 6d, 7d and processed during 23 to 30 Sep, 2005 (enviromental temperature: 23.0 to 30.5℃), the latter was subdivided into eight subgroups at 1d, 2d, 4d, 8d, 12d, 16d, 20d and processed during 31 Nov to 20 Dec, 2005 (enviromental temperature: 2.5 to 9.0 ℃), three per subgroup. Being indoors, ventilation, protected from light and...