Skeletal muscle uncoupling protein 3 expression is a determinant of energy expenditure in Pima Indians.
The recent discovery of uncoupling protein (UCP)-2 and UCP-3, and their high expression in skeletal muscle, has renewed interest in a possible role for these proteins in underlying the variability in energy expenditure and therefore metabolic efficiency. Using reverse transcription-polymerase chain reaction, levels of expression of UCP-2 and long and short forms of UCP-3 were measured in skeletal muscle of 19 nondiabetic, male Pima Indians covering a wide range of body weight. Twenty-four-hour energy expenditure was measured in a respiratory chamber in 16 of these individuals. BMI was negatively correlated with the expression levels of the long (r = -0.53, P = 0.025) and short (r = -0.46, P = 0.047) forms of UCP-3. BMI was not correlated with UCP-2 expression. Metabolic rate during sleep, adjusted for fat-free mass and fat mass, was positively correlated with the long form of UCP-3 (r = 0.69, P = 0.006). These results indicate that UCP-3 may be a determinant of energy expenditure and metabolic efficiency in Pima Indians.
Schrauwen
P
P
Department of Human Biology, Maastricht University, The Netherlands.
Xia
J
J
Bogardus
C
C
Pratley
R E
RE
Ravussin
E
E
D000328:Adult; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002352:Carrier Proteins / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D007198:Indians, North American; D007473:Ion Channels; D008297:Male; D008875:Middle Aged; D024101:Mitochondrial Proteins; D018482:Muscle, Skeletal / Q000378:metabolism*; D012890:Sleep / Q000502:physiology; D000071247:Uncoupling Protein 3
D002352:Carrier Proteins; D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604392:UCP3 protein, human; D000071247:Uncoupling Protein 3