Hepatic mitochondrial efficiency in lines of mice differing in feed intake.
PMID 23463560 · Journal of animal science · 2013 · DOI 10.2527/jas.2012-5975
Authors: T W Murphy; J M McDonald; M K Nielsen
Abstract
Selection was practiced for high (MH) and low (ML) heat loss using direct calorimetry to create lines of mice differing in feed intake per unit average BW (FI/BW). A total of 25 generations of selection was practiced during maintenance of an unselected control (MC). As a percentage of MC, mice of MH and ML lines differed in heat loss and FI/BW by 56 and 34%, respectively, when selection ceased. The purpose of this study was to determine hepatic mitochondrial efficiency in mice at maintenance across the genetic lines. After measurement of feed intakeand BW over a 2-wk period, mice were euthanized, and their livers were extracted. Livers were homogenized and mitochondria were isolated in buffer for measurement of oxygen consumption and, hence, mitochondrial activity using a Clark-type oxygen electrode. Mitochondria of ML mice expressed greater (P < 0.03) respiratory control ratio by 22% than that for MH mice, revealing greater degree of uncoupling during electron transport in MH mice. Difference in FI/BW (P < 0.001) was large with MH mice consuming 34% more than ML mice. The respiratory control ratio differed between mice of MH and ML lines as expected; however, regression analysis revealed that it explained essentially no variation in feed intake per BW.
Animal Nutritional Physiological Phenomena; Animals; Body Composition; Body Temperature Regulation; Body Weight; Cell Respiration; Energy Metabolism; Feeding Behavior; Liver; Male; Mice; Mitochondria; Models, Biological; Organ Size; Regression Analysis; Selection, Genetic; Weight Gain
Cite
T W Murphy; J M McDonald; M K Nielsen. Hepatic mitochondrial efficiency in lines of mice differing in feed intake. Journal of animal science (2013). PMID 23463560. DOI 10.2527/jas.2012-5975.