Absence of estrogen receptors delays myoregeneration and leads to intermuscular adipogenesis in a low estrogen status: Morphological comparisons in estrogen receptor alpha and beta knock out mice.

This study aimed to investigate the function of estrogen receptors (ERs) in myoregeneration and intermuscular adipogenesis. Ovariectomized (OVX) ERα knockout (KO) mice and ERβ KO mice were used to assess the effect of estrogen on the myoregenerative process. Tibialis anterior muscle was collected on days 7, 10, and 14 after cardiotoxin injection to assess myotube morphology and adipogenesis area. Regenerated myotubes from OVX-ERβ KO mice were consistently smaller in diameter than those from OVX-ERα KO and OVX-wild-type mice, whereas the adipogenesis area of OVX-ERβ KO mice was consistently greater than that of the other types. Therefore, ERβ may be an influential factor in promoting myoregeneration and adipogenesis inhibition compared to ERα.