Hossein Shirvani, Saleh Rahmati-Ahmadabad, David Robert Broom, and Reza Mirnejad
The hypothalamus controls metabolism and feeding behavior via several signals with other tissues. Exercise and supplements can change hypothalamic signaling pathways, so the present study investigated the influence of eccentric resistance training and β-Hydroxy-β-methylbutyrate free acid supplement on PGC-1α expression, serum irisin, nesfatin-1 and resistin concentrations. Thirty-two male rats (8 weeks old, 200±17 g body mass) were randomized to control (CON), β-Hydroxy-β-methylbutyrate free acid (HMB) supplementation, eccentric resistance training (ERT), and β-Hydroxy-β-methylbutyrate free acid supplementation plus eccentric resistance training (HMB+ERT) groups. Training groups undertook eccentric resistance training (6 weeks, 3 times a week) and supplement groups consumed HMB-FA orally (76 mg/kg/day). Twenty-four hours after the last training session, rats were sacrificed after which serum and triceps brachii muscle were collected and sent to the laboratory for analyses. Two-way ANOVA and Pearson correlation were employed (significant level: P< 0.05). The results showed that eccentric resistance training increases skeletal muscle PGC-1α gene expression, as well as serum levels of irisin and nesfatin-1 (P= 0.001). Eccentric resistance training decreases serum concentration of resistin (P= 0.001). HMB-FA supplement increases skeletal muscle PGC-1α gene expression (P= 0.002), as well as serum concentartion of irisin and nesfatin-1 (P= 0.001). HMB-FA decreases the serum concentration of resistin (P= 0.001). Significant correlations were observed between PGC-1α gene expression and serum concentrations of irisin, nesfatin-1 and resistin. Generally, HMB-FA with eccentric resistance training may induce crosstalk between releasing peptides from other tissues and increases maximal strength. Their combination had a more substantial effect than each intervention in isolation.