Oxytocin is involved in steroid hormone–stimulated bovine satellite cell proliferation and differentiation in vitro

Abstract Sex steroid hormones are used in the meat industry due to their ability to regulate muscle hypertrophy. However, the mechanisms underlying their action are not fully elucidated. Recent reports demonstrate that steroid hormones increase oxytocin (OXT) expression in skeletal muscle, indicating that OXT may play a role in satellite cell activity. This hypothesis was tested using steroid hormones (17β-estradiol [E2]; trenbolone acetate [TBA]), tamoxifen (TAM), OXT, and atosiban (A: OXT receptor inhibitor) applied to bovine satellite cells (BSCs) to investigate BSC regulation by OXT. Oxytocin alone increased fusion index ( P P P P P P P OXT expression increased ( P P MyoD and MyoG expression in proliferating BSC. During BSC differentiation, OXT expression increased ( P MyoG expression increased ( P P MyoG expression during BSC differentiation. These results indicate that OXT is involved in steroid hormone–stimulated BSC activity.