Meeting Abstract
105.1 Thursday, Jan. 7 What does it take to exercise while holding your breath? The underlying secrets of myoglobin regulation in seal muscle cells. DE MIRANDA JR., M.A.*; CABLE, A.E.; KANATOUS, S.B.; Colorado State University ; Colorado State University; Colorado State University demiranda.michael@gmail.com
The purpose of this study was to determine if cultured Weddell seal (Leptonychotes weddelli) primary skeletal muscle cells inherently possess adaptations to diving under hypoxia. Weddell seal primary skeletal muscle cells were cultured along side a C2C12 mouse skeletal muscle cell line and differentiated under normoxic (21% O2) and hypoxic (0.5% O2) conditions. Weddell seals cells were grown and differentiated in either low glucose DMEM supplemented with 2.5% lipid mixture or high glucose DMEM supplemented with 5% lipid mixture. After 7 days of differentiation into mature myotubes the cells were harvested and analyzed for differences in myoglobin concentration using a myoglobin assay and 2D gel electrophoresis. We hypothesized that cultured Weddell seal primary skeletal muscle cells would have elevated myoglobin concentrations when compared to cultured C2C12 mouse skeletal muscle cells. Our results indicate that under hypoxia the mouse cells down-regulated myoglobin by 31%. Interestingly under hypoxia, Weddell seal cells up-regulated myoglobin to concentrations 12-fold greater. In addition, myoglobin concentrations increased in Weddell seal cells, under normoxic and hypoxic conditions, as a result of increasing concentrations of lipid supplemented to the growth media. In contrast, lipid supplemented to the growth media of the mouse cells had no effect on myoglobin concentrations in either oxygen condition. Based on our results, we conclude that Weddell seal skeletal muscle cells differentially regulate myoglobin in response to hypoxia as compared to mouse skeletal muscle cells, which may be attributed to inherent adaptations to the low oxygen associated with breath-hold diving.
