0615 GMT April 23, 2019
In the study, a special type of stem cells was taken from the hearts of newborn rats and injected into the hearts of old rats, average age 22 months. Other rats from the same age group were given saline shots instead, UPI reported.
Baseline heart function was measured in all the rats, using echocardiograms, treadmill stress tests and blood analysis.
The group of older rats underwent an additional round of testing one month after receiving the stem cells from the hearts of the young rats.
The old rats who were given stem cells showed better heart function, a 20-percent increase in exercise capacity and, oddly enough, an improved ability to regrow hair.
Co-primary investigator Dr. Eduardo Marban, director of the Cedars-Sinai Medical Center Heart Institute in Los Angeles, said, "Our previous lab studies and human clinical trials have shown promise in treating heart failure using cardiac [heart] stem cell infusions.
"Now we find that these specialized stem cells could turn out to reverse problems associated with aging of the heart.
"The way the cells work to reverse aging is fascinating.
"They secrete tiny vesicles that are chock-full of signaling molecules such as RNA and proteins. The vesicles from young cells appear to contain all the needed instructions to turn back the clock."
But more research is needed, the investigators said.
Co-primary investigator Dr. Lilian Grigorian-Shamagian, a postdoctoral researcher at Cedars-Sinai, added, "This study didn't measure whether receiving the [specialized] cells extended life spans, so we have a lot more work to do.
"We have much to study, including whether [heart stem cells] need to come from a young donor to have the same rejuvenating effects."
The findings were published in the European Heart Journal.