A Novel Method for Preserving Human Lungs Using a Super-Cooling System

To ensure the suitable preservation of isolated lungs, a super-cooling system was used to cool water to temperatures as low as −5°C without freezing. After lung tissues were obtained from patients with lung cancer, they were kept at −5°C or 4°C for as many as 5 days, and then they were histologically and biochemically examined. To evaluate biochemical stability, tissues after storage were passively sensitized with immunoglobulin E and then incubated with anti-immunoglobulin-E antibody. Although tissues preserved at −5°C for 5 days had an almost normal appearance with intact cilia on bronchial epithelium and normal endothelium, tissues stored at 4°C showed degradation of these structures. Single-stranded DNA, a sign of DNA cleavage, was frequently noted in tissues stored at 4°C, but only rarely observed at −5°C. A significant amount of cysteinyl-leukotrienes was generated from tissues stored at −5°C for 3 days, but there was no response to antibody stimulation from tissues stored at 4°C. Super-cooling systems may provide useful applications as a novel preserving method.