Voelcker Academy

Research Symposium 2010

 

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Stephen Santos

Abnormal Glucose Tolerance in the Longest Lived Rodent, the Naked Mole-rat. A new Model for Longevity and Diabetes Research

Stephen Santos

Mentor: Dr. Rochelle Buffenstein

The Naked Mole-Rat (NMR) is a novel model in aging research. It lives for 30+ years, which is 10x longer than that of a similar sized mouse. Naked Mole-Rats do not show signs of aging until they are the equivalent of a 100 year old human (24 years for the NMR). By an early age the NMR has sustained high levels of oxidative damage. No tumors have been found to date in the NMR. Their gestational period is 70 days. NMRs are unique in the fact that they do not maintain a constant body temperature on their own; they require the aid from external factors. The Naked Mole-Rat is an Eusocial rodent living in colonies similar to ants or bees with one queen and a limited number of breeding males. All of the other colony members do not reproduce. Colonies of the NMR can have up to 290 NMRs with a mean of 75 NMRs. The Queen Naked Mole develops a larger spine in order to aid in her movement through the burrows of the colony (NMRs are strictly subterranean). She weans her litter of between 12-27 pups at four weeks. The pups are fed feces in order to develop fauna in their guts. Levels of CO2 are high while levels of O2 are extremely low in the burrows. The ability to live in hypoxic atmospheres with high levels of carbon dioxide is helped by the NMR's lack of Substance P (a neurotransmitter). Diabetes has not been shown in NMRs. They have low fasting blood glucose levels, abnormal Glucose Tolerance Test readings, abnormal pancreas arrangement, and unmeasureable insulin levels. NMR's are extremely sensitive to exogenous insulin. Further research will include: the measuring of glucose levels, studying results from Glucose Tolerance Tests and Insulin Tolerance Tests, and Western Blots to measure proteins used in glucose metabolism. Some NMR fun facts include: The NMR has 19 different recognizable sounds, its burrows run for miles and can be up to eight feet deep, and the Queen is either pregnant and/or lactating throughout her entire reign.