A recipe for growing bigger hearts, found in the blood of pythons

In comic books, many superheroes have gained extraordinary powers after being transfused with the (often modified or irradiated) blood of animals. But, as so often happens, life proves stranger than fiction. At the University of Colorado, Boulder, a group of mice have grown bigger hearts after scientists injected them a chemical cocktail, inspired by the blood of pythons. When the situation demands it, the muscles of mammal hearts grow larger and pump more vigorously. That’s useful for pregnant women who need to pump for two, toddlers who need to fuel their rapid growth, or athletes who need to power their regularly exercise. But growing hearts can also be bad news if they’re triggered by genetic disorders, high blood pressure or heart attacks. These situations can cause “hypertrophic cardiomyopathy”, where the heart’s thickening walls force it to work harder to pump blood. To understand how hearts get bigger, Cecilia Riquelme turned ...