Fat chance: the effect of lipid supplementation on adapting to hypoxia in skeletal muscle cells

Abstract

Diving mammals are a unique type of endurance athlete that undergo apnea during exercise, yet rely on an aerobic lipid based metabolism to fuel their primary swimming muscles. A hallmark adaptation that allows diving mammals to endure aerobic exercise in a seemingly hypoxic environment is the high abundance of myoglobin in their working skeletal muscle. Our previous research found in response to hypoxic conditions alone the expression of myoglobin significantly decreased in mouse cell lines. In contrast, recent results showed that unlike terrestrial mammal muscle cells the concentration of myoglobin increased under hypoxic conditions in seal primary muscle cells. The purpose of this study was to determine the effects of lipid supplementation on myoglobin expression in mouse C2C12 and seal primary muscle cells. Myoglobin assays were used to quantify differences in myoglobin expression. As previously seen in our seal muscle cells, myoglobin expression was significantly increased in C2C12 cell lines with lipid supplementation under hypoxic but not normoxic conditions, thus implying that lipids play a role in driving the expression of myoglobin under hypoxic conditions in mammalian muscle cells.