80.3 Friday, Jan. 6 Changes in Pulmonary Surfactant in Deer Mice (Peromyscus maniculatus) at High Altitude DIAZ, S.*; THALER, C. D.; SHIRKEY, N. J.; BROWN, T.; CARDULLO, R. A.; HAMMOND, K. A.; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside firstname.lastname@example.org
A complex mixture of proteins and lipids, known as the pulmonary surfactant system, reduces the surface tension at the air-liquid interface within the lung. While the lipids are primarily responsible for lowering surface tension, surfactant proteins (SP-B & SP-C) are critical in the adsorption and spreading of lipids at the air-liquid interface and modify the properties of the surface film. Previous studies in our lab have demonstrated differential increases in the surfactant lipids that increase membrane fluidity in deer mice living at high altitude in cold conditions. As a result we predicted that mice acclimated to high altitude will also up-regulate the amounts of surfactant proteins present in their lung in an effort to offset the destruction of the lipids and aid in the recycling of lipids to and from the air-liquid interface. The total surfactant protein content of the lung surfactants is 43% higher in animals acclimated to high altitude than it is in animals acclimated to low altitude and we are currently using Western blotting to determine if this change reflects changes in SP-B, SP-C, or both. These results provide insight into how changes in the composition of the surfactant facilitate the overall plasticity of the surfactant system and aid in the maintenance of higher metabolic rates of deer mice at high altitude.