Orbital fat-derived stem cells maintained homeostasis of testosterone. (A) Torsion–detorsion (T/D) resulted in reducing serum testosterone, and orbital fat-derived stem cells (OFSCs) progressively recovered the testosterone level in the first 7 days. (B) T/D transiently increased the level of luteinizing hormone (LH) on day 3, but OFSCs did not regulate LH in the first 7 days. (C) The follicle-stimulating hormone (FSH) level was triggered by T/D testicular injury on day 3 and day 7, and OFSCs returned the FSH level back to normal status on day 7. *P <0.05, **P <0.01, ***P <0.001.