ANN ARBOR---The same protein that helped Maurice Greene become the "world's fastest man" at this summer's Olympic Games in Australia could one day help millions of Americans who suffer from a common type of progressive heart failure, according to a new animal study by scientists at the University of Michigan Medical School.
This protein, called parvalbumin, helps skeletal muscle fibers in the arms and legs contract and relax rapidly and efficiently. Olympic sprinters have high levels of parvalbumin in their skeletal muscle, which helps explain why they can run faster than the rest of us, according to Joseph M. Metzger, Ph.D., associate professor of physiology and of internal medicine in the U-M Medical School. Parvalbumin works like a sponge helping skeletal muscle cells relax faster by soaking up calcium ions.
In a study published in the Jan. 15 issue of the Journal of Clinical Investigation, Metzger and a team of U-M researchers show for the first time that parvalbumin also can improve heart function in laboratory rats---restoring normal relaxation rates in hearts with a condition that mimics the abnormally slow cardiac relaxation common in human heart failure.
"Although important and challenging scientific obstacles remain, our findings raise the intriguing possibility of one day using parvalbumin therapy to treat progressive heart failure in humans," Metzger says.
Exacerbated by high-fat diets and not enough exercise, heart failure is a growing medical problem affecting approximately five million Americans, with more than 700,000 new cases reported each year. About 40 percent of the time, heart failure is associated with a condition called diastolic dysfunction where the heart contracts normally, but doesn't relax fast enough to allow the cardiac chambers to fill with blood before the next contraction.
"In a healthy, living heart all cells work together like an orchestra with one conductor," Metzger says. "In a heart with diastolic dys
Contact: Sally Pobojewski
University of Michigan