Fig 1. A schematic diagram showing the detailed animal groups involved in this study.

Experimental mice were randomly assigned into four groups, including Non-MI, MI-3 h, MI-24 h and MI-72 h. Non-surgical mice served as non-MI control [17] and were euthanized after echocardiography. Mice in MI groups were euthanized at 3 h, 24 h and 72 h post-MI respectively after echocardiography. Blood samples and organs were collected from all experimental animals to measure plasma corin, troponin, cardiac corin, ANP and BNP, and to do histologic examination.