Protective effect and mechanism of estrogen receptor β on myocardial infarction in mice.

The protective effect and the mechanism of estrogen receptor beta (ER beta) on myocardial infarction (MI) in mice were explored. A total of 12 female Tg-ER beta transgenic mice and 12 non-transgenic littermate control (NLC) wild-type C57 mice were used for the present study. Both transgenic and wild-type mice had similar baseline data such as age, sex, and weight. The mouse model of MI was established by coronary artery ligation method, and the cardiac structure and function changes of the mouse were observed by ultrasonic echocardiography on days 1, 3 and 7 after the operation. RT-PCR method was used to detect the expression of collagen I, alpha-SMA, TGF-beta mRNA in the mouse heart, and Masson staining was used to detect cardiac fibrosis. At 3 days after operation, echocardiographic posterior wall thickness at end diastole (PWTD) and end systolic PWTS of Tg-ER beta mice were significantly reduced, and left ventricular systolic diameter and left ventricular diastolic diameter significantly increased (P<0.05) compared with NLC mice. The levels of expression of Tg-ER beta cardiac tissue collagen I, a-SMA, TGF-beta mRNA were significantly lower than those in the NLC mice (P<0.05). In conclusion, Tg-ER beta exerts a protective effect on MI.