Most pet parents dread the idea of their four-legged companion aging and would do just about anything to increase their natural lifespan, just as long as their quality of life were good. Scientists have been investigating a compound named rapamycin as a potential anti-aging therapy for dogs.
Discovered on Easter Island, rapamycin was initially investigated for its anti-fungal properties and its ability to suppress the immune system. This made it useful for reducing organ rejection in people who had been given an organ transplant. Later studies indicated that this drug could increase the lifespan of yeast and mice, which is quite an exciting discovery. It's not yet fully understood how rapamycin exerts its effect on aging. It appears that it targets a specific protein known as mTOR, and inhibition of mTOR's effects has been shown to have a positive effect on lifespan.
These results caught the eye of researchers from the University of Washington who shared their lives with senior pets. They founded the Dog Aging Project to investigate ways in which a pet's lifespan can be extended. However, they're not just looking at increasing the length of time a pet lives. Their focus is on extending the years a pet is healthy and enjoying life rather than increasing the lifespan of a pet that's struggling with age-related diseases. Their goal is a longer quality life rather than just a longer life.
One of their investigations involves a longitudinal study to try to identify what factors allow dogs to enjoy a long and healthy life. Individual dogs of a number of different breeds will be monitored throughout their lives to study their environment and any biological factors that may influence lifespan.
Another study is looking at rapamycin and how it may be used to extend a pet's life. In the first phase of the study, 24 middle-aged dogs were given rapamycin for ten weeks. These dogs showed no adverse effects from the use of the medication and their heart function improved significantly. Although these results don't necessarily indicate that the treatment will slow down aging, it does imply it's worth further investigation of its effects. This leads to the second phase of the rapamycin study where the scientists will look at not only the drug's effects on heart function, but also on the immune system and cognitive function. They'll also evaluate the effect of rapamycin on the incidence of cancer.
The Dog Aging Project and its studies into rapamycin will help researchers to understand how dogs age and whether the process can be slowed. This might have important implications for people, too. Dogs and humans are biologically very alike. It's not easy to conduct long-term studies on people to evaluate aging and the factors that influence it, because they are expensive and take a long time. Dogs have a shorter lifespan. They also reproduce and grow to maturity quicker, so it takes less time to get results from any investigations. The studies into aging in dogs and whether rapamycin can slow it down may just improve the healthy lifespan of human beings, too.