Selection for growth does not affect apparent energetic efficiency of jejunal glucose uptake in mice.
Five-wk-old male mice from high growth (M16) and randomly bred control (ICR) lines, plus their reciprocal crosses, ICR x M16 and M16 x ICR, were used to investigate whether whole-body O2 consumption, jejunal respiration, jejunal glucose absorption and the apparent energetic efficiency of jejunal active glucose uptake in mice are altered by genetic selection for growth as well as by heterosis and maternal effects. Whole-body O2 consumption was measured in 12 mice from each line or cross. The mice were later killed for measurement of jejunal O2, using tissue respiration chambers and jejunal glucose transport determined by 3H-3-O-methylglucose accumulation. No heterosis or maternal effects were detected in jejunal glucose active transport and active glucose uptake. Selection for growth (M16 vs. ICR) increased daily gain (1.54 vs. 1.09 g, P < 0.001), small intestinal length and weight, but did not enhance jejunal glucose transport. The apparent energetic efficiency of jejunal active glucose uptake among lines was not different (54.0, 50.4, 51.6 and 47.1 nmol ATP expended/nmol glucose uptake for M16, ICR, M16 x ICR and ICR x M16, respectively, P > 0.63). Selection for growth in mice did not result in more energetically efficient jejunal glucose absorption.
Department of Animal Science, North Carolina State University, Raleigh 27695, USA.
Y K
YK
Fan
W J
WJ
Croom
E J
EJ
Eisen
L R
LR
Daniel
B L
BL
Black
B W
BW
McBride
D000818:Animals; D001947:Breeding; D004734:Energy Metabolism / Q000502:physiology*; D005947:Glucose / Q000493:pharmacokinetics*; D006823:Hybrid Vigor / Q000502:physiology; D007583:Jejunum / Q000378:metabolism*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D012641:Selection, Genetic
D005947:Glucose