The Molecular Mechanisms of Exercise on Skeletal Muscular Water and Prevention of Postmenopausal Sarcopenia

Abstract

We investigated the effects of estrogen on AQP4 and NKCC1 in the skeletal muscle by using estrogen-deficient animals following resistance exercise training. Female adult rats （10 weeks old） were divided into the following 6 groups: sham sedentary, sham climbing training, ovariectomy sedentary, ovariectomy climbing training, ovariectomy plus estrogen treatment sedentary, and ovariectomy plus estrogen treatment climbing training groups. The estrogen deficiency is caused by the ovariectomy. After 8 weeks of climbing training, the weight of the flexor halluces longus （FHL） muscles were significantly increased in the sham climbing training group but not in in the ovariectomy climbing training group. On the contrary, ovariectomy plus estrogen treatment resulted in exercise-induced muscle hypertrophy. AQP4 and NKCC1 protein expressions tended to be decreased after ovariectomy, and the estrogen treatment reversed this decrease of AQP4 and NKCC1 in ovariectomized animals. Nevertheless, these differences regarding protein expression among the groups were not significant. Therefore, these data suggest that estrogen regulated exercise-induced muscle hypertrophy but did not affect the expressions of AQP4 and NKCC1 in the skeletal muscle.