Mice, who usually live up to four years in captivity, have had their lives extended due to a drug called rapamycin. Scientists, at the University of Washington in Seattle, are initially testing this drug on Golden Retrievers, Labradors, and German Shepherds in the hope this drug will have the same effect on dogs and on humans. It’s called the Dog Aging Project.
“Those three breeds are in the size range we are considering for the initial study, but the study is not limited to those breeds,” Dr. Matt Kaeberlein of the University of Washington in Seattle tells DogTime. “There will also be a second larger rapamycin study and a longitudinal study of aging that dogs of all sizes and breeds are potentially eligible for.”
Kaeberlein also says people can sign their pets up to be considered for enrollment in both studies at the Dog Aging Project “Join Us” page.
Researchers have found that rapamycinhas been shown to extend the lives of mice by more than 10 percent. So, researchers are hoping to host trial experiments on humans. Since we live a lot longer than mice, the research to see if this works and if it has positive benefits on humans could take several years.
“If you give rapamycin to 20-month-old mice when they are in their equivalent of our middle age,” Kaeberlein tells The Guardian,“You can see pretty profound benefits in terms of rejuvenating their bodies and increasing their lifespans.
“The crucial point is that at that age, a mouse is the equivalent age of a nine-year-old dog. So if we now start giving the drug to middle-aged dogs, we have a chance of finding out in only a few years that it works on larger animals. The equivalent for that age for humans is 60. However, it will take much longer to obtain results from humans to see if the drug is working or not.”
According to Kaeberlein, pet dogs experience many of the same environmental influences as their owners. “We are doing this research to try to help dogs but we are well aware that what we learn could point the way to using rapamycin on humans. So anything we learn about other factors that influence the drug’s usefulness is going to be important.”
If the benefits are positive, rapamycin could be added to pet food in order to extend the lives of household dogs. “As organisms age, inflammation can increase and that is related to many disorders,”Kaeberlein adds. “But that is not the only thing that rapamycin does. It also turns on a process calledautophagy which is in effect the process by which cells dispose of the garbage that builds up inside them. It helps clear out the rubbish in our cells.”
Rapamycinis not a panacea; it is associated with severe side effects such as diabetes-like symptoms and complications of the lung. “These side-effects usually only occur when people take high doses of rapamycin during transplant surgery,” Kaeberlein says. “The key point about the trial that we are planning is that we will use only very low doses of rapamycin which will be added to the dogs’ food over long periods, probably years.
“Rapamycin is never given to people during transplant surgery. It is used to prevent rejection, but people don’t start getting the drug until after the transplant surgery is complete and the wound has healed.
A few dozen dogs will be tested. Golden Retrievers, Labradors, and German Shepherds were selected for the initial trials because of their life spans, which are usually 11 to 12 years of age and because they tend to get heart disease and cancer.