Anti-Aging Scientists Extend Lifespan of Oldest Living Lab Rat

Scientists working on an experimental anti-ageing therapy claim to have broken a record by extending the lifespan of a lab rat called Sima. Named after the Hindi word for “limit” or “boundary”, Sima is the last remaining survivor from a group of rodents that received infusions of blood plasma taken from young animals to see if the treatment prolonged their lives. Sima, who was born on February 28, 2019, has lived for 47 months, surpassing the 45.5 months believed to be the oldest age recorded in scientific literature for a female Sprague-Dawley rat, the researchers say. So far, Sima has outlived her closest rival in the study by nearly six months. “We have the oldest living female Sprague Dawley rat,” said Dr Harold Katcher, a former biology professor at the University of Maryland, now chief scientific officer at Yuvan Research, a California-based startup.

Researchers have rushed to produce and trial therapies based on young blood plasma after numerous experiments found that infusions could reinvigorate aging organs and tissues. But while studies have found benefits for rodents, there is no evidence to date that the somewhat vampiric approach to youthfulness will help humans dodge the passage of time, despite the best wishes of Silicon Valley. The results from Katcher’s latest study will be written up when Sima dies, but data gathered so far suggests that eight rats that received placebo infusions of saline lived for 34 to 38 months, while eight that received a purified and concentrated form of blood plasma, called E5, lived for 38 to 47 months. They also had improved grip strength. Rats normally live for two to three years, though a contender for the oldest ever is a brown rat that survived on a restricted calorie diet for 4.6 years.

A patent filing on the potential therapy describes how plasma from young mammals is purified and concentrated before use. Some components, such as platelets, are removed, as they can trigger immune reactions. The patent names pigs, cows, goats, sheep and humans as possible donors. The amount of plasma needed to produce a single concentrated dose is at least as much as the recipient has in their entire body, it states. If the therapy ever shows promise in humans — large trials are needed in more animals first — Katcher believes the plasma could be collected from pigs at abbatoirs.