PLN and myocardial ischemia: The interesting findings in the present study were that the acupuncture pretreatment could reduce the elevated ECG ST segments, cardiac arrhythmias, and myocardial infarct size significantly in the rats subjected to the myocardial ischemia and reperfusion via enhancing the content of A2b receptor and regulating the expression of the key calcium signaling components including RyR2, SERCA2a, and P-PLB(S16)/PLB and subsequently impact the ratio of Troponin C/Troponin I in cardiac muscle (Table 2).