Ly on myocardial cells in the protective effect of the failing heart. We isolated cardiac myocytes of OVX+ISO and OVX+ISO+G-1 group, cultured with b1-AR Epigenetics antagonist CGP20712A, b2AR antagonit ICI118551, we found that treatment with CGP or ICI separately could not abolish the improvement of the cell contraction., but combination treatment with CGP and ICI 25033180 could abolish the improvement completely. This indicated that the protective of G-1 may associate with both b1-AR and b2-AR. #3Q3Although there is a group with antagonist group, the ligand specificity in vivo is still limitation in vivo study, forexample the antagonist drugs may reach to the liver, brain or other organs, which confer the systolic changes of the bodies. The sympathetic nervous system is critically involved in the regulation of cardiac function through b-AR. Activation of b1-AR results in augmentation of cardiac activity (positive inotropic effect), including an increase in heart rate and atria-ventricle conduction velocity and enhancement of myocardial contraction [33]. Roth DM has pointed that overexpression of b1 receptors caused cardiac damage [25]. Our laboratory has found that the expression of b1-AR Epigenetic Reader Domain increased in 
ovariectomized female rats compared with the Sham group [7], which indicated that estrogen may play an important role in regulate the expression of b1-AR thus conferred cardiac protection effect. In this paper, we found that the expression of b1-AR increased in OVX group, G-1 or E2 treatment decreased it, and we didn’t observed cardiac damage indications in OVX group, here we speculated ovariectomized is just a risk factor for hearts. However ISO treatment decreased the expression of b1-AR and produced injury effect which may be attributed to continuous stimulation of catecholamine led to decline in receptor number and reduce of the function [4], G-1 or E2 treatment could reduce the injury and increased the expression of b1-AR compared with OVX+ISO group. Taken together, G-1 or E2 treatment regulated protein b1-AR in the protective effects. Unlike b1AR, activation of b2-AR plays a beneficial role in hearts. Sustained b1-AR stimulation promotes apoptotic death of cardiomyocytes, sustained stimulation of b2-AR protects myocytes against a wide range of apoptotic insults [27]. Similarly, some studies showed that overexpression of b2-AR conferred cardiac protective effect in the heart [8,28] which was consistent with our results. In our opinion, treatment with the estrogen hormone agonist G1 could increase the expression of b2-AR. Interestingly, other hormones or models could also regulate the expression of b2-AR in the body. For instance, Penna C has reported sub-chronic nandrolone pretreatment increased the expression of b2-AR [28], thyroid hormones increased the mRNA of b2-AR in heart [29], and in diabetic heart model, the expression of b2-AR decreased [30]. However whether the mechanism of protective effects of G-1 which changed the expression of b2-AR is direct or indirect effects such as regulating the secretion of other hormones is unknown, the mechanisms remain to be further studied. Taken all together, in this study we found that chronic treatment with G-1 attenuated heart failure by increased the expression of b2-AR and normalized the expression of b1-AR in ovariectomized rats. This is the first time we have reported chronic treatment with G-1 is beneficial for the heart failure.GPR30 and Chronic CardioprotectionMaterials and Methods Animals and Reagents.Ly on myocardial cells in the protective effect of the failing heart. We isolated cardiac myocytes of OVX+ISO and OVX+ISO+G-1 group, cultured with b1-AR antagonist CGP20712A, b2AR antagonit ICI118551, we found that treatment with CGP or ICI separately could not abolish the improvement of the cell contraction., but combination treatment with CGP and ICI 25033180 could abolish the improvement completely. This indicated that the protective of G-1 may associate with both b1-AR and b2-AR. #3Q3Although there is a group with antagonist group, the ligand specificity in vivo is still limitation in vivo study, forexample the antagonist drugs may reach to the liver, brain or other organs, which confer the systolic changes of the bodies. The sympathetic nervous system is critically involved in the regulation of cardiac function through b-AR. Activation of b1-AR results in augmentation of cardiac activity (positive inotropic effect), including an increase in heart rate and atria-ventricle conduction velocity and enhancement of myocardial contraction [33]. Roth DM has pointed that overexpression of b1 receptors caused cardiac damage [25]. Our laboratory has found that the expression of b1-AR increased in ovariectomized female rats compared with the Sham group [7], which indicated that estrogen may play an important role in regulate the expression of b1-AR thus conferred cardiac protection effect. In this paper, we found that the expression of b1-AR increased in OVX group, G-1 or E2 treatment decreased it, and we didn’t observed cardiac damage indications in OVX group, here we speculated ovariectomized is just a risk factor for hearts. However ISO treatment decreased the expression of b1-AR and produced injury effect which may be attributed to continuous stimulation of catecholamine led to decline in receptor number and reduce of the function [4], G-1 or E2 treatment could reduce the injury and increased the expression of b1-AR compared with OVX+ISO group. Taken together, G-1 or E2 treatment regulated protein b1-AR in the protective effects. Unlike b1AR, activation of b2-AR plays a beneficial role in hearts. Sustained b1-AR stimulation promotes apoptotic death of cardiomyocytes, sustained stimulation of b2-AR protects myocytes against a wide range of apoptotic insults [27]. Similarly, some studies showed that overexpression of b2-AR conferred cardiac protective effect in the heart [8,28] which was consistent with our results. In our opinion, treatment with the estrogen hormone agonist G1 could increase the expression of b2-AR. Interestingly, other hormones or models could also regulate the expression of b2-AR in the body. For instance, Penna C has reported sub-chronic nandrolone pretreatment increased the expression of b2-AR [28], thyroid hormones increased the mRNA of b2-AR in heart [29], and in diabetic heart model, the expression of b2-AR decreased [30]. However whether the mechanism of protective effects of G-1 which changed the expression of b2-AR is direct or indirect effects such as regulating the secretion of other hormones is unknown, the mechanisms remain to be further studied. Taken all together, in this study we found that chronic treatment with G-1 attenuated heart failure by increased 
the expression of b2-AR and normalized the expression of b1-AR in ovariectomized rats. This is the first time we have reported chronic treatment with G-1 is beneficial for the heart failure.GPR30 and Chronic CardioprotectionMaterials and Methods Animals and Reagents.
