Fig. 5
From: Metabolic reprogramming involving glycolysis in the hibernating brown bear skeletal muscle
Muscle glycogen content is increased and serum fatty acid profiles are changed in winter bear muscles. As illustrated on representative electron micrographs of brown bear vastus lateralis muscle (panel A), intramyofibrillar (green) and especially intermyofibrillar (yellow) glycogen granules accumulate in skeletal muscle of hibernating bears (lower panel), whereas their presence was largely undetectable in active summer bears (upper panel) at this magnification level. Glycogen content was measured in bear muscles (panel B; N = 7 per group). Circulating levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were assessed in bear serum (panel C; N = 4 serum mixes per season). Data are expressed as means ± sem. Statistical significance is shown for paired student t-tests (* P < 0.05; ** P < 0.02) and post-hoc Tukey tests that followed one-way ANOVA (values that do not share the same superscript letter are significantly different; P < 0.05)