Calorie restriction in mice: Effects on body composition, daily activity, metabolic rate, mitochondrial reactive oxygen species production, and membrane fatty acid composition

Abstract

Different levels of calorie restriction (CR) (125, 85, 50, or 40 kcal/wk for 1, 3, and 6 months) were examined in mice by using the paradigm of Weindruch and colleagues. Lean and total body mass increased on 125 and 85 kcal/wk, but there was negligible growth on low-energy intake. There was no CR-induced reduction in either daily activity or mass-specific metabolic rate. There was no CR-effect on in vitro reactive oxygen species production by liver or muscle mitochondria at 3 months, but after 6 months the effect was significantly reduced in liver mitochondria from 40 kcal/wk mice compared to 125 kcal/wk mice. Changes in the fatty acid composition of phospholipids from liver, kidneys, heart, brain, and skeletal muscle were observed following 1 month of CR. Copyright 2006 by The Gerontological Society of America.