Prolonged longevity in naked mole-rats: age-related changes in metabolism, body composition and gastrointestinal function.
Aging is characterized by declines in all physiological processes and concomitant changes in body composition. Age-related changes in metabolism, body composition and gastrointestinal function were investigated in naked mole-rats (Heterocephalus glaber), rodents that exhibit extended longevity. Maximum lifespan of these 40 g rodents (>27 year) is approximately 9 times greater than predicted allometrically. We investigated changes in basal metabolic rate (BMR), body composition and intestinal glucose transport in 1, 5, 10 and 20-year-old male individuals. Body composition was measured using dual X-ray absorptiometry and activity of sodium glucose co-transporters (SGLT1) determined using everted gut sleeves. One-year-olds had lower body mass than other age cohorts, as they had not attained full adult form. Among the 5, 10, and 20-year-olds, no age-related changes in body mass, BMR, percentage body fat, fat-free mass or bone mineral density were found. SGLT1 activity declined moderately (<20%) from 5 to 20 years and was similar at 10-20 years, whereas age-related declines are 40-60% in mice. Although mole-rats have low metabolic rates, their prolonged longevity results in a lifetime energy expenditure more than 4 times that of mice. Since lifetime energy expenditure is an important index of potential exposure to oxidative damage, naked mole-rats may be valuable for studying mechanisms of aging.
O'Connor
Timothy P
TP
Department of Biology, City College of City University of New York, 138th Street and Convent Avenue, New York, NY 10031, USA.
Lee
Angela
A
Jarvis
Jennifer U M
JU
Buffenstein
Rochelle
R
D000375:Aging / Q000502:physiology; D000818:Animals; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D005753:Gastric Mucosa / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D007408:Intestinal Absorption / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism*; D008136:Longevity / Q000502:physiology*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D019577:Mole Rats / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D051269:Sodium-Glucose Transporter 1
D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D051269:Sodium-Glucose Transporter 1; D005947:Glucose