Association of beta hydroxy butyrate and branched-chain amino acids with BDNF-Akt-mTOR-FOXO1 signaling in gastrocnemius muscle of fasted rats undergoing mild endurance exercise. (A): Mass Spectrometry analysis of gastrocnemius muscle levels of BHB, Leu, Ile, and Val; (B): Western immunoblot analysis of gastrocnemius muscle proteins involved in BDNF-mTOR signaling, with quantified data shown below. Of note: P70S6K phosphorylation versus Actin ratios are depicted, the ratio with the non-phosphorylated protein did not vary. (A,B): Analysis was carried out comparing control rats with rats subjected to exercise, fasting, or fasting with exercise. (N = 4, n = 3). One way ANOVA was carried out followed by a Newman Keuls post-hoc test. * p < 0.05 vs. C, † p < 0.05 vs. C and F, ‡ p < 0.05 vs. C, F and FE, # p < 0.05 vs. E, F, and C, ## p < 0.05 vs. E and C, § p < 0.05 vs. FE. Abbreviations: N: biological replications, n: technical replications. BHB: beta hydroxy butyrate; Data are shown as means ± SEM.