Carey 9723860 This project will examine the role of stress proteins in the process of mammalian hibernation. Stress proteins are made by cells in response to stressful conditions such as excessive heat, cold, lack of glucose, viruses and chemical toxicants. Stress proteins help to prevent cellular death in part by protecting cellular proteins that may be damaged by stress, or by helping the process of protein degradation when proteins are irreversibly damaged by stress. Animals that hibernate provide a natural system with which to study the adaptive significance of stress proteins because of the extreme shifts in body temperature and metabolism that occur over the course of the annual cycle, as well as during the transitions from low temperature to high temperature that hibernators undergo periodically throughout the winter. The PI will compare levels of stress proteins in intestine, liver, heart and skeletal muscle of fed, fasted and hibernating 13-lined ground squirrels and in mitochondria isolated from liver, skeletal muscle and heart in these groups. Tissues samples will be obtained at precise points during the periodic arousals that occur during the hibernation season. The PI will also correlate changes in stress proteins with the extent of protein damage during hibernation.
