Effects of estrogen replacement and lower androgen status on skeletal muscle collagen and myofibrillar protein synthesis in postmenopausal women.

Our aim was to determine synthesis rate of myofibrillar and collagen proteins in 20 postmenopausal women, who were either nonusers (Controls) or users of estrogen replacement therapy (ERT) after hysterectomy/oophorectomy. Myofibrillar and muscle collagen protein fractional synthesis rate (FSR) were determined in a nonexercised leg and 24 hours after exercise in the contralateral leg. A significant interaction between treatment and mechanical loading was observed in myofibrillar protein FSR.