Estrogen replacement increases β-arrestin2 expression in cardiac tissues in ovariectomized rats

Objective To observe the expression ofβ-arrestin2 in cardiac tissues of ovariectomzied(OVX)rats,and to explore the role ofβ-arrestin2 in estrogen-mediated cardiovascular protection in OVX rats.Methods OVX rats were evaluated by monitoring the serum levels of estrogen and the ratio of uterine weight to body weight.The cardiovascular function of rats was assessed by measuring the ratio of heart weight to body weight,blood pressure and heart rate after estrogen replacement treatment for 4weeks,Western blotting analysis was performed to detect the protein expression ofβ-arrestin1,β-arrestin2 and angiotensin receptor type 1(AT1R)in the cardiac tissues.Results Compared with rats in the sham group,the serum estrogen level and the ratio of uterine weight to body weight in OVX rats were decreased significantly(P0.05);meanwhile,the cardiovascular parameters including blood pressure,heart rate and the ratio of heart weight to body weight were significantly increased(P0.05)in OVX rats,and they were attenuated after treatment with estrogen replacement.Compared with the sham controls,the cardiac expression ofβ-arrestin2 was decreased significantly in OVX rats(P0.05),with up-regulated estrogen expression and unchanged expression ofβ-arrestin1 and AT1R.Conclusion β-Arrestin2 expression is decreased in the cardiac tissues of OVX rats,which can be increased by estrogen replacement therapy.