Hearts under stress need to work harder, and cardiac cells bulk up to facilitate this output. But healthy heart cell growth, caused by exercise or pregnancy, occurs by a different mechanism than so-called pathological growth, induced by heart attack or high blood pressure.
To better understand the difference, and possibly to uncover a way to preferentially encourage healthy growth, cardiologist Leslie Leinwand of the University of Colorado in Boulder studied Burmese python hearts, which balloon by 40% after the snakes’ monthly meal without incurring harm. In a paper published today in Science, Leinwand and her colleagues identified a mixture of three fatty acids in the pythons’ blood that were activated during cardiac growth: myristic, palmitic, and palmitoleic acids. And, when she injected them into mice, their hearts exhibited healthy growth — although they expanded by less than 10%.
The next step is to study whether this fatty acid mixture can heal or treat diseased mouse hearts and then, eventually, human. “The question is whether this growth is truly physiological and is it going to help the heart function better,” says Rong Tian, who studies cardiovascular metabolism at the University of Washington in Seattle.
Image: Burmese python digesting, courtesy of Stephen M. Secor