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Students at the University of Alabama are used to seeing a 3-meter (10 foot)-long Burmese python slithering down the hallways of the biology department. Following close behind is physiologist Stephen Secor's lab team as they monitor the python's heart.
Secor got wrapped up in studying Burmese pythons after observing their amazing digestive feats. The snakes--which grow to lengths of 7 m (23 ft) and can weigh more than 100 kilograms (220 pounds)--can swallow an animal their own size whole, and then go months without eating. That's like a person eating 600 hamburger patties in one sitting!
Within two or three days after a meal, most of the python's internal organs double in size and its heart size increases 40 percent. "Their hearts grow because so much is being asked of them when snakes are digesting this meal," says Secor. "They're having to pump blood to these now extremely active organs."
Over the years, Secor's team has uncovered a lot about pythons' hearts. Even so, no one understood how the snakes' hearts got to be super size so quickly. Then Secor got a phone call from Leslie Leinwand, a molecular biologist at the University of Colorado. She wanted to tackle the mystery in the hope that the snakes' secrets would lead to treatments for human heart disease.
HEART OF THE MYSTERY
Leinwand thought that python cardiac hypertrophy--an increase in the size of heart cells--might help people. Human hearts can also undergo hypertrophy, either for good or for bad. After the heart's chambers fill with blood, the heart muscle contracts to pump the blood throughout the body (see Inside a Human Heart, p. 14). In harmful cardiac hypertrophy, the heart muscle thickens and the size of the chambers decreases, making the heart less efficient at pumping.
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