Lee Richard E, Damodaran Krishnan, Yi Shu-Xia, Lorigan Gary A
aDepartment of Zoology, Miami University, Oxford, OH 45056, USA.
Cryobiology. 2006 Jun;52(3):459-63. doi: 10.1016/j.cryobiol.2006.03.003.
The rapid cold-hardening (RCH) response not only confers dramatic protection against cold-shock (non-freezing) injury, but also "instantaneously" enhances organismal performance. Since cold-shock injury is associated with damage to the cell membrane, we investigated the relationship between RCH and changes in cold tolerance and membrane fluidity at the cellular level. None of the adult flies (Sarcophaga bullata) in the cold-shocked treatment group survived direct transfer to -8 degrees C for 2 h; in contrast, 64.5% of flies in the RCH group survived exposure to -8 degrees C. Differences between the treatment groups also were reflected at the cellular level; only 21.3% of fat body cells in the cold-shocked group survived compared to 68.5% in the RCH group. Using 31P solid-state NMR spectroscopy, we determined that membrane fluidity increased concurrently with rapid cold-hardening of fat body cells. This result suggests that membrane characteristics may be modified very rapidly to protect cells against cold-shock injury.
快速冷硬化（RCH）反应不仅能显著保护机体免受冷休克（非冷冻）损伤，还能“即时”提高机体性能。由于冷休克损伤与细胞膜损伤有关，我们在细胞水平上研究了RCH与耐寒性变化及膜流动性之间的关系。冷休克处理组的成年蝇（棕尾别麻蝇）直接转移至-8℃ 2小时后无一生还；相比之下，RCH组有64.5%的蝇在暴露于-8℃后存活。处理组之间的差异在细胞水平上也有体现；冷休克组脂肪体细胞仅有21.3%存活，而RCH组为68.5%。通过31P固态核磁共振光谱，我们确定膜流动性随着脂肪体细胞的快速冷硬化而同时增加。这一结果表明，膜特性可能会非常迅速地发生改变，以保护细胞免受冷休克损伤。
