Mechanical loading influences bone mass through estrogen receptor alpha.

Mechanical loading influences bone mass and architecture through a cascade of cellular events that involve estrogen receptor alpha (ERalpha). An implication of this is that bone architecture is more adaptive to mechanical loading when the estrogen receptor number is high, as during adolescence, and less sensitive when the estrogen receptor number is low, as occurs postmenopausally, during amenorrhea, or after ovariectomy.