[Storage temperature and skin xenograft survival]

Pieces of guinea pig skin, 0.3-0.4mm in thickness, 1.5cm in diameter, were stored at different temperatures. The skin fragments were divided into five groups: (1) fresh skin; (2) skin stored at 4 degrees C for 48hr; (3) skin stored at -20 degrees C for 48hr; (4) skin stored at -80 degrees C for 48hr; (5) skin stored at -196 degrees C for 48hr. The cryoprotective agent was the same in all groups except group 2. The experimental skin was grafted on both sides of the back of anesthetized mice, two pieces of skin of the same group for one mouse. The grafted skin survival was determined by daily observation. The skin was considered as rejected if necrosis took place in 80% of the grafted skin. Grafted skin biopsy was performed for pathological examination. The results showed that the survival days of stored skin xenografts were prolonged as the stored temperature lowered. The pathological changes (neutrophil infiltration, thrombosis of small vessels, necrosis of epidermal and dermal cells) were mild and delayed as the stored temperature lowered. So low temperature may decrease the antigenicity of the stored skin.