(University of California - San Francisco) Although most victims survive the 735,000 heart attacks that occur annually in the US, their heart tissue is often irreparably damaged -- unlike many other cells in the body, once injured, heart cells cannot regenerate. According to a new UC San Francisco study, the issue may date back to our earliest mammalian ancestors, which may have lost the ability to regenerate heart tissue in exchange for endothermy -- or 'warm-bloodedness.'
Original Article: Thyroid hormone helped our ancestors survive but left us susceptible