The effect of exercise training in cold on shivering and nonshivering thermogenesis in adult and aged C57BL/6J mice.
To understand the mechanisms of improvement of cold-induced heat production in aged mice following exercise training, the relative contributions of shivering and nonshivering thermogenesis to cold-induced metabolic responses were assessed in adult and aged C57BL/6J male mice, which inhabited sedentarily at room temperature, or were subjected either to a regimen of moderate intensity exercise training at 6 degrees C, or to sedentary repeated exposures to the same temperature. The main findings were that (1) aged mice had greater cold-induced nonshivering thermogenesis, but lower shivering than adult mice; (2) exercise training in a cold environment enhanced cold-induced nonshivering thermogenesis in adult mice, but suppressed it in aged animals; (3) exercise training in a cold environment increased shivering thermogenesis in both age groups, but this increase was much greater in aged mice; (4) the increase of cold-induced shivering thermogenesis was mainly responsible for increased cold tolerance in aged mice after exercise training in a cold environment.
Laboratory of Behavioral Sciences, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
V I
VI
Shefer
M I
MI
Talan
D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000777:Anesthetics / Q000494:pharmacology; D000818:Animals; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D003080:Cold Temperature; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012768:Shivering / Q000502:physiology*; D014520:Urethane / Q000494:pharmacology; D014673:Vecuronium Bromide / Q000494:pharmacology
D000777:Anesthetics; D003473:Neuromuscular Nondepolarizing Agents; D014520:Urethane; D014673:Vecuronium Bromide