SAN ANTONIO (Dec. 21, 2010) – In a colony of 1,600 animals from a species known for its extraordinary longevity, this one stood out. After living a world-record three decades in captivity, a naked mole rat — affectionately known as Old Man — has died at the Barshop Institute for Longevity and Aging Studies, part of The University of Texas Health Science Center at San Antonio. He was at least 32 years old.
The animal was part of the largest naked mole rat colony in the United States, maintained at the Barshop Institute by Rochelle Buffenstein, Ph.D., professor of physiology. The Methuselah of the Barshop Institute had already reached adult mass by the time he was captured in Lerata, Kenya, on June 5, 1980, indicating he was at least 1½ to 2 years old at the time, Dr. Buffenstein said.
“The very fact he was in captivity for 30 years was impressive,” she said. “From a scientific standpoint, this animal was extremely important because of its longevity and the facts we learned from it and its peers.”
In his last days, Old Man was frail yet resilient. “He was a decrepit, sarcopenic individual who started looking his age about five years ago,” Dr. Buffenstein said. “At his death he was still the dominant male in the colony, the first to feed, and possibly still the breeding male.” Sarcopenia is loss of muscle associated with aging.
Native to East Africa, naked mole rats are burrowing rodents with a distinctive appearance. They are hairless, as the name suggests, with wrinkled pinkish skin, tiny eyes and protruding front teeth.
The naked mole rat’s remarkable traits go beyond its appearance: It has an astonishingly long life span compared with other rodents. A naked mole rat typically lives between 25 and 30 years, compared with a 2- to 3-year life span for a mouse. The capacity of a naked mole rat to resist cancer and maintain protein integrity in the face of high oxidative damage makes it an ideal animal model for aging and biomedical research.
These animals also appear able to maintain good health for at least 80 percent of their long lives, and show no age-related decline in activity, bone health and reproductive capacity.
1980 trip to Kenya
Dr. Buffenstein’s research mentor, Jenny Jarvis, Ph.D., was the first person to bring naked mole rats into captivity and kept them for many years at Cape Town University in South Africa. Dr. Buffenstein went with her in 1980 to Kenya to collect these interesting rodents.
“From the first group of naked mole rats in captivity we learned that they are eusocial, or highly socially organized mammals that live in colonies with only one breeding female and a system of workers,” Dr. Buffenstein said. “More recently we have learned that their bodies are markedly resistant to cancer, oxidative stress and various other toxins. These are small animals, but they are making large contributions to our understanding of long life and aging.”
Later Dr. Buffenstein moved to the United States, transferring a sizable colony of naked mole rats to City College of New York. In 2007 she brought the colony to the Barshop Institute, which includes the comparative biology of aging among its research focuses. Comparative gerontologists study the different rates of aging among various species to understand what governs the aging process, and they take particular interest in exceptionally long-lived species like naked mole rats.
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