REN and myocardial infarction: It may be noted that myocardial injury due to myocardial infarction is known to result in activations of the sympathetic nervous system (SNS), posterior pituitary, endothelium and platelets, which result in the release of different vasoactive hormones such as norepinephrine, vasopressin, endothelins and serotonin, respectively, whereas the activation of the renin–angiotensin system (RAS) promotes the formation of angiotensin II upon the release of renin from the kidney.