Osteocalcin is an osteoblast-derived peptide mainly found in the bone matrix but also in circulation. A recent investigation suggested that osteocalcin mediated acute stress response (ASR) by inhibiting parasympathetic tone in mice and humans. We propose a hypothesis that osteocalcin is regulated by the skeleton movement and glucocorticoids, and inhibition of the parasympathetic tone by osteocalcin may indicate a therapeutic target in the treatment of acute myocardial infarction (AMI).