Meeting Abstract
P3.86 Thursday, Jan. 6 Want to be an elite diver? Get fat! The underlying secrets of myoglobin regulation in Weddell seal muscle cells DE MIRANDA JR., M.A.*; SCHLATER, A.E.; GREEN, T.L.; KANATOUS, S.B.; Colorado State University; Colorado State University; Colorado State University; Colorado State University demiranda.michael@gmail.com
The purpose of this study was to uncover factors that drive the regulation of myoglobin in Weddell seals (Leptonychotes weddelli) to concentrations up to ten-fold greater than terrestrial mammals. 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 high glucose DMEM supplemented with 2.5% and 5% lipid mixtures. After 7 days of differentiation into mature myotubes the cells were harvested and analyzed for differences in myoglobin concentration using a myoglobin assay and 2-D 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 under both normoxic and hypoxic conditions. Our results indicate that under hypoxia the mouse cells down-regulated myoglobin by 31%. Surprisingly under hypoxia, Weddell seal cells actually up-regulated myoglobin to concentrations 12-fold greater than the mouse cells. Interestingly, in response to increasing concentrations of lipid supplemented to the growth media, myoglobin concentrations increased further in the Weddell seal cells under both oxygen conditions. Based on our results, we conclude that Weddell seal primary skeletal muscle cells differentially up-regulate myoglobin in response to hypoxia and lipids, which may be the key factors that drive myoglobin to levels necessary to become an elite breath-hold diver.
