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Effect of long‐term caloric restriction on mitochondrial function in skeletal muscle and non‐exercise activity in aged rats
Author(s) -
Schimke Jill M,
Walrand Stephane,
Klaus Katherine A,
Morse Dawn,
Short Kevin R,
Novak Colleen,
Levine James A,
Nair K. Sreekumaran
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1094.7
Subject(s) - ucp3 , skeletal muscle , medicine , sarcopenia , endocrinology , caloric theory , chemistry , citrate synthase , biology , uncoupling protein , biochemistry , enzyme , obesity , brown adipose tissue
Aging is associated with a concomitant decline in non exercise activity (NEA) and mitochondrial ATP production rate (MAPR) in skeletal muscle. To determine whether caloric restriction (CR) could prevent the decline in MAPR and NEA we studied young (Y, 7 month‐old, n=8), old (O, 27 month‐old, n=7) and old caloric‐restricted F344/BN rats (OCR, 27 month‐old, 40% CR from 16 weeks of age, n=7). Energy expenditure (kcal/d/gBW) was lower in O (0.311±0.005) than Y (0.365±0.004) and was higher in OCR (0.341±0.008) (P<0.05). Muscle mass (mg/gBW) of O was lower than Y, and Y and OCR are similar (Y=0.96±0.18, O=0.71±0.16, OCR=1.03±0.04; P<0.05 OCR vs O). Citrate synthase activity and MAPR were lower in both O and OCR than Y (P<0.05). UCP3 protein level was higher in soleus and plantaris muscles from O rats than Y and OCR (p<0.005). CR lowered UCP3 expression in skeletal muscles to the level in Y rats (p<0.005 OCR vs O). CR also lowered expression of mRNA levels of NADH4 (p<0.005 OCR vs O). NEA levels were lower in O and OCR rats than in Y (p<0.05 Y vs O and OCR). In conclusion, the decline in mitochondrial functions during aging can be counteracted by CR but an age‐related decline in activity levels could not be prevented. Funded by NIH RO1 AG09531 and Mayo Foundation.