Macronutrient diet intake of the lethal yellow agouti (Ay/a) mouse.
To examine the effect of chronic endogenous melanocortin receptor (MC-R) antagonism on macronutrient diet selection, Ay/a mice that ectopically overexpress the MC-R antagonist, agouti, were fed a three-choice macronutrient diet of pure fat, carbohydrate, and protein. Ay/a mice gained more weight and consumed a greater proportion of their daily intake from fat and less from carbohydrate than wild-type littermates did. The increased fat preference was present immediately, and persisted throughout the 7-week long experiment. Protein intake was greater for Ay/a mice; however, the proportion of protein intake to total intake was similar between mouse types. Ovarian fat pads of Ay/a mice comprised a greater percentage of total body weight that that from wild-type littermates. These results suggest that endogenous inhibition of MC-Rs mediate the increased fat intake in growing mice.
Koegler
F H
FH
Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA.
Schaffhauser
A O
AO
Mynatt
R L
RL
York
D A
DA
Bray
G A
GA
D000818:Animals; D001835:Body Weight / Q000235:genetics; D004032:Diet; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D004435:Eating / Q000235:genetics*; D005260:Female; D005518:Food Preferences / Q000502:physiology; D006200:Hair Color / Q000235:genetics*; D009074:Melanocyte-Stimulating Hormones / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000235:genetics*; D011979:Receptors, Pituitary Hormone / Q000235:genetics*
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D011979:Receptors, Pituitary Hormone; C029446:MSH receptor; D009074:Melanocyte-Stimulating Hormones