Too small to see with the naked eye, the microscopic cell pulses with the potential to heal the body’s strongest muscle.

University researchers have discovered undeveloped adult stem cells in the hearts of animals that share many of the same characteristics of embryonic stem cells.

The study results were published in the February edition of Nature Clinical Practice Cardiovascular Medicine.

The cells have as much, if not more, potential as many of the other cells researchers have worked with previously, said paper co-author Doris Taylor, the director of the University’s Center for Cardiovascular Repair.

“If you give them the right nutrients and media that they need, they’ll actually develop into beating heart cells in a dish,” she said.

Fellow author Dr. Harald Ott, the former scientific director of the center, said University scientists are the first to discover this specific kind of cell.

“What we’ve shown is that our cells actually express the same markers as embryonic stem cells,” he said.

The researchers used cells found in rats and mice, Ott said, to show their methods could work for multiple species.

The next step, Taylor said, is to find a comparable cell in humans, which they believe is likely to happen. Recently, the scientists successfully isolated this type of cell from pigs, animals physiologically similar to humans.

“The bottom line is we’ve found these cells. We’re excited by these cells and we’re hopeful we can now start working with surgeons to find the same cells in biopsies of human hearts,” she said.

If found, the cells could be used in clinical trials to develop new treatments for patients suffering from heart failure, repair damage after a person has a heart attack or possibly create new tissue for people in need of transplants.

“Basically, we have the components we need to begin to build new hearts,” Taylor said.

The project began in December 2004 and ended last May, said Thomas Matthiesen, an associate scientist in the center and study author.

In that year and a half, Matthiesen said he and fellow University scientist Saik-Kia Goh handled many of the day-to-day operations of the research.

First, they would isolate the cells by chopping up pieces of heart tissue and exposing it to enzymes in a media culture, he said.

“After a few days, the cells would start to surface above the meat chunks and those were our cells,” Matthiesen said.

Then they characterized the cells, Goh said, which is how they determined their embryonic characteristics. After that, scientists injected the cells into damaged hearts where they observed the cells repairing the tissue.

Part of what makes these cells so unique, he said, is they can grow into many different kinds of tissues, such as embryonic cells, but also can improve heart function.

“That’s a pretty powerful one-two punch,” he said.