Figure 1.The apelin-insulin-oxytocin axis: a multi-hormonal network for muscle health. Schematic representation of the coordinated effects of insulin, oxytocin, and apelin on muscle health and systemic homeostasis. The colored arrows illustrate how these hormones are influenced by one another. Dashed black arrows denote downstream signaling pathways and indicate pathway-mediated effects on healthy muscle tissue. Key downstream pathways include MAPK/AMPK/mTOR (apelin), PI3K/AKT/mTOR/Foxo/MAPK (insulin), and Akt/Foxo/PKC (oxytocin). All three hormones promote muscle satellite cell (MuSC) activation, proliferation, metabolism, proteostasis, mitochondrial biogenesis, and myogenic differentiation, ultimately contributing to overall metabolic homeostasis. The diagram illustrates the synergistic and overlapping mechanisms by which these hormones maintain healthy muscle tissue and anabolic-catabolic balance.
