GPER1 and obesity due to melanocortin 4 receptor deficiency: To determine the potential involvement of GPER1 in estrogen deficiency–induced obesity, insulin resistance, and hepatic lipid accumulation, the OVX female mice in which bilateral surgical removal of the ovaries were treated with GPER1-specific agonist G1 at dose of 5 mg/kg/2 days by gavage for 20 weeks.