Regulator of G‑protein signaling 12 (RGS12) is a regulatory factor that is involved in various physiological processes. However, the role of RGS12 in myocardial ischemia/reperfusion injury (MIRI) currently remains unclear. The present study established a mouse model of MIRI by ligating the left main coronary artery followed by reperfusion. In addition, mouse HL‑1 cells were cultured in a hypoxic and serum‑free medium, followed by reoxygenation to establish an