|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 2003 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 2002 : ¥1,500,000 (Direct Cost : ¥1,500,000)
An animal experimental study was carried out to investigate availability of mRNA expressions of tissue-type plasminogen activator (tPA) and fibronectin, and inflammatory cell dynamics for wound age estimation of bruises. The bruises ware made by compressing the dorsal skin of mice with 2 iron plates with holes, 3mm in diameter. The mice were killed at 1, 3, 8, 24, 72, 144, or 240 hours post-injury. tPA mRNA expression peaked at 1 hour, and increased slightly at 72 hours post-injury. It was detected in epidermal cells, fibroblasts, and endothelial cells before and after injury, and from 3 hours in neutrophils and from 72 hours in macrophages, respectively. tPA was considered to play an essential role in the first step of tissue remodeling. A slight increase of tPA mRNA expression at later phase might be related to epidermal proliferation. On the other hand, expression of fibronectin mRNA was biphasic. It peaked at 1 hour, and significantly increase at 144 hours post-injury. Acute increase of fibronection would be due to tissue reaction of mechanical injury, and activation of coagulation cascade. Proriferation of the fibroblasts would be major cause of the late phase peak. Examination of the correlation of microscopic changes, such as inflammatory cell dynamics and epidermal thickening, with mRNA expression of tPA, fibronectin and other cytokines, would be informative for bruise healing and dating in the acute and chronic phases.