Rats being studied in laboratory

U-M Researchers Share Rat Model with Scholars Worldwide

Run longer. Be healthier. It’s a pretty obvious connection—those who exercise more often are less susceptible to disease. But how exactly does a man’s aerobic capacity affect his chances of suffering a spontaneous heart attack? And how does a woman’s running ability impact her brain function?

The answers could stem from a laboratory housed at the University of Michigan, where Steve Britton, PhD, and Lauren Koch, PhD, have developed a unique rat model that provides scientists worldwide with a significant resource to study how exercise endurance capacity correlates with disease risks.

Twenty years ago, the U-M researchers developed a selective breeding process to generate rats that were either low-capacity runners or high-capacity runners.

“I am not aware of any other models that have been developed by direct artificial selection for aerobic capacity,” said Britton, professor of anesthesiology. They measure the rats’ endurance on treadmills, and those that can run for longer periods of time breed together.

“We don’t train them to run,” said Koch, associate professor of anesthesiology. “This is just what they do. And in terms of our rat population, our lows are low and our highs are high. There are no real middle runners anymore. ”

The scientists have bred 36 generations of rats, with the high-capacity runners peaking at 78 minutes on the treadmill. The low-capacity runners exhaust at 15 minutes.

“We want to understand disease, we want to understand health and we want to understand physical performance,” Britton said. “These rats allow us to do that. Not everything is going to be equivalent to what you find in a human, but they’re both mammals and they both have similar genomes, so the things we can do in rats are much more extensive than what can be done in humans.”

Britton and Koch have worked with more than 400 scholars at 60 institutions worldwide on research involving the U-M rat model.

Researchers at Colorado State University are studying how exercise capacity can impact your chances of being diagnosed with cancer. Duke University researchers are testing how exercise endurance relates to brain function. And U-M researchers, like Koch, are utilizing the rat model to study the importance of exercise endurance in relation to longevity and aging.

Their initial theory that aerobic capacity plays a critical role in health and longevity seems to have panned out. The rats with elevated aerobic endurance are shown to be more resistant to obesity, fatty liver disease, sleep disorders and memory loss. And the average life expectancy of the high-capacity runners is between 28 and 45 percent higher than those rats with low aerobic endurance.

“There’s one main goal here: that is to get information that can lead to translation to help patients,” Britton said.

This story was originally published by the U-M Office of Research on September 16, 2015.